251362921 has 2 divisors, whose sum is σ = 251362922. Its totient is φ = 251362920.

The previous prime is 251362919. The next prime is 251362939. The reversal of 251362921 is 129263152.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 175933696 + 75429225 = 13264^2 + 8685^2 .

It is a cyclic number.

It is not a de Polignac number, because 251362921 - 2¹ = 251362919 is a prime.

Together with 251362919, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (251362961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125681460 + 125681461.

It is an arithmetic number, because the mean of its divisors is an integer number (125681461).

Almost surely, 2^251362921 is an apocalyptic number.

It is an amenable number.

251362921 is a deficient number, since it is larger than the sum of its proper divisors (1).

251362921 is an equidigital number, since it uses as much as digits as its factorization.

251362921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6480, while the sum is 31.

The square root of 251362921 is about 15854.4290657217. The cubic root of 251362921 is about 631.1032328004.

The spelling of 251362921 in words is "two hundred fifty-one million, three hundred sixty-two thousand, nine hundred twenty-one".