251501310491 has 2 divisors, whose sum is σ = 251501310492. Its totient is φ = 251501310490.

The previous prime is 251501310481. The next prime is 251501310521. The reversal of 251501310491 is 194013105152.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-251501310491 is a prime.

It is a super-2 number, since 2×251501310491² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (251501310451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125750655245 + 125750655246.

It is an arithmetic number, because the mean of its divisors is an integer number (125750655246).

Almost surely, 2^251501310491 is an apocalyptic number.

251501310491 is a deficient number, since it is larger than the sum of its proper divisors (1).

251501310491 is an equidigital number, since it uses as much as digits as its factorization.

251501310491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5400, while the sum is 32.

The spelling of 251501310491 in words is "two hundred fifty-one billion, five hundred one million, three hundred ten thousand, four hundred ninety-one".