251956457 has 2 divisors, whose sum is σ = 251956458. Its totient is φ = 251956456.

The previous prime is 251956451. The next prime is 251956459. The reversal of 251956457 is 754659152.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 229098496 + 22857961 = 15136^2 + 4781^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-251956457 is a prime.

Together with 251956459, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (251956451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125978228 + 125978229.

It is an arithmetic number, because the mean of its divisors is an integer number (125978229).

Almost surely, 2^251956457 is an apocalyptic number.

It is an amenable number.

251956457 is a deficient number, since it is larger than the sum of its proper divisors (1).

251956457 is an equidigital number, since it uses as much as digits as its factorization.

251956457 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 378000, while the sum is 44.

The square root of 251956457 is about 15873.1363315509. The cubic root of 251956457 is about 631.5995776111.

The spelling of 251956457 in words is "two hundred fifty-one million, nine hundred fifty-six thousand, four hundred fifty-seven".