251081231 has 2 divisors, whose sum is σ = 251081232. Its totient is φ = 251081230.

The previous prime is 251081203. The next prime is 251081239. The reversal of 251081231 is 132180152.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 251081231 - 2²⁶ = 183972367 is a prime.

It is a super-2 number, since 2×251081231² = 126083569120950722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 251081197 and 251081206.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (251081239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125540615 + 125540616.

It is an arithmetic number, because the mean of its divisors is an integer number (125540616).

Almost surely, 2^251081231 is an apocalyptic number.

251081231 is a deficient number, since it is larger than the sum of its proper divisors (1).

251081231 is an equidigital number, since it uses as much as digits as its factorization.

251081231 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 480, while the sum is 23.

The square root of 251081231 is about 15845.5429379999. The cubic root of 251081231 is about 630.8673959497.

The spelling of 251081231 in words is "two hundred fifty-one million, eighty-one thousand, two hundred thirty-one".