250 (number)

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249 250 251
Cardinal two hundred fifty
Ordinal 250th
(two hundred and fiftieth)
Factorization 2 × 53
Roman numeral CCL
Binary 111110102
Ternary 1000213
Quaternary 33224
Quinary 20005
Senary 10546
Octal 3728
Duodecimal 18A12
Hexadecimal FA16
Vigesimal CA20
Base 36 6Y36

250 (two hundred [and] fifty) is the natural number following 249 and preceding 251.

As a Mandarin slang term, 250 (二百五 pinyin èrbǎiwǔ) is an insult meaning "stupid person" or "simpleton". The expression is based on bàndiàozi (半弔子 or 半吊子). In ancient China, copper coins were grouped by stringing them together through the square holes in the center; originally 1000 was a unit of currency called a diao. Ban diao zi literally means half a diao (500 coins), which is a slang term referring to a person who is inadequate in skills or mental abilities. Since modest Chinese scholars may call themselves ban diao zi to humbly deprecate their own expertise, ban diao zi is not necessarily a pejorative term. On the other hand, Er bai wu (250) is half of a ban diao zi and it is an insult.

Two hundred [and] fifty is also:

  • SMTP status code for mail action completed.
  • In the Holy Bible, the number of men rebelling against Moses, who were swallowed up by a fire. (Numbers 26:10).
  • The number of Pokémon originally available in Pokémon Gold and Silver before Celebi was added.


251 is prime, Sophie Germain prime, sum of three consecutive primes (79 + 83 + 89), sum of seven consecutive primes (23 + 29 + 31 + 37 + 41 + 43 + 47), Chen prime, Eisenstein prime with no imaginary part.

252 = 22·32·7, refactorable number, Harshad number, central binomial coefficient (10, 5), the largest one divisible by all coefficients in the previous line, member of the Mian–Chowla sequence

253 = 11·23, triangular number, star number, centered heptagonal number, centered nonagonal number, Blum integer

254 = 2·127, Mertens function returns 0, nontotient

255 has its own article.

256 has its own article.

257 is prime, Fermat prime, balanced prime, Chen prime, Eisenstein prime with no imaginary part

258 = 2·3·43, sphenic number, sum of four consecutive primes (59 + 61 + 67 + 71), nontotient

259 = 7·37, repdigit in base 6 (1111).