In Spanish it is correct to write dos mil (separately, not together) and it is correct to write veintitrés (with accent), dos mil veintitrés.
Now, how do you write the other numbers in Spanish and which ones have a tilde? You will find these answers in this post:
How do you write out numbers in Spanish? Guide
1 = uno
2 = dos
3 = tres
4 = cuatro
5 = cinco
6 = seis
7 = siete
8 = ocho
9 = nueve
10 = diez
11 = once
12 = doce
13 = trece
14 = catorce
15 = quince
16 = dieciséis
17 = diecisiete
18 = dieciocho
19 = diecinueve
20 = veinte
21 = veintiuno
22 = veintidós
23 = veintitrés
24 = veinticuatro
25 = veinticinco
26 = veintiséis
27 = veintisiete
28 = veintiocho
29 = veintinueve
30 = treinta
The numbers that are written in one word are:
✅ the numbers from zero to twenty-nine.
✅ the tens (treinta, cuarenta, etc.)
✅ the hundreds (cien, doscientos, etc.).
Examples:
Tenemos cinco hijos y siete nietos.
(We have five children and seven grandchildren.)
Este departamento tiene cuarenta empleados en total.
(This department has forty employees in all.)
Los novios tienen doscientos invitados a la boda.
(The bride and groom have two hundred wedding guests.)
When are numbers written with letters?
Letters are generally used instead of numbers in literary works and non-technical texts, unless they are very complex numbers.
Round numbers that can be written in a single word (trescientos mil, dos millones, etc.).
Examples:
Ganó doce millones en la lotería.
(He won twelve million in the lottery.)
Fueron más de sesenta mil personas al festival.
(More than sixty thousand people attended the festival.)
- Two numbers joined by the conjunction y (up to noventa y nueve).
Examples:
Tuvo cuarenta y dos grados de fiebre.
(He had a fever of forty-two degrees.)
En esta clase hay treinta y siete alumnos.
(There are thirty-seven students in this class.)
- Not overly complex numbers referring to units of measurement (written by name).
Examples:
El hotel más cercano está a cincuenta kilómetros. (no “km.”)
(The nearest hotel is fifty kilometers away.)
Necesito veinte metros de cinta.
(I need twenty meters of tape.)
- Approximate numbers or those used with expressive intent.
Examples:
Hablamos como veinte veces al día.
(We talk about twenty times a day.)
Había treinta mil y pico de personas en el concierto.
(There were thirty-something thousand people at the concert.)
Creo que tiene cuarenta y pico de años.
(I think he is forty-something years old.)
- Numbers that are part of idioms or set phrases.
Examples:
Ella es la número uno en esta industria.
(She’s number one in this industry.)
Al final, vinieron cinco gatos locos a la reunión de padres.
(At the end, “five crazy cats” – Spanish set phrase- came to the parents’ meeting.)
Me llama cada dos por tres.
(She calls me every so often. – Spanish idiom)
When are numbers written with digits?
In writing, numbers are used instead of letters in scientific and technical texts, in mathematical operations, statistical computations, inventories, tables, graphs or any other context, on posters, labels, newspaper headlines and advertising texts.
- Numbers that can be written (in letters) from four or more words.
Examples:
Recibimos un total de 1574 cartas desde todo el mundo.
(We received a total of 1574 letters from all over the world.
Es un pueblo muy pequeño, con sólo 685 habitantes.
(It is a very small town, with only 685 inhabitants.)
- Percentages greater than ten (less than ten can be written in letters or numbers). They are also written without spaces between the number and the symbol (% = percent).
Examples:
La inflación subió un 15,4% desde el año pasado.
(Inflation is up 15.4% since last year.)
Tiene una conversión del 36%.
(It has a conversion of 36%.)
- Decimal numbers.
Example:
El índice de desempleo es de 5,8.
(The unemployment rate is 5.8.)
- Numbers that are followed by unit of measure symbols.
Examples:
La maratón es de 12 km.
(The marathon is 12 km.)
La temperatura subirá a los 45° esta semana.
(The temperature will rise to 45° this week.)
Debes precalentar el horno a 200° por 10 mins.
(You should preheat the oven to 200° for 10 mins.)
- Numbers following nouns that identify them.
Examples:
Vamos a leer el artículo de la página 14.
(Let’s read the article on page 14.)
Estamos en la habitación 312 en el piso 12.
(We are in room 312 on the 12th floor.)
