251163708491 has 16 divisors (see below), whose sum is σ = 260322709248. Its totient is φ = 242219964000.

The previous prime is 251163708487. The next prime is 251163708493. The reversal of 251163708491 is 194807361152.

It is a cyclic number.

It is not a de Polignac number, because 251163708491 - 2² = 251163708487 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (251163708493) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 384200 + ... + 806186.

It is an arithmetic number, because the mean of its divisors is an integer number (16270169328).

It is a 2-persistent number, because it is pandigital, and so is 2⋅251163708491 = 502327416982, but 3⋅251163708491 = 753491125473 is not.

Almost surely, 2^251163708491 is an apocalyptic number.

251163708491 is a deficient number, since it is larger than the sum of its proper divisors (9159000757).

251163708491 is a wasteful number, since it uses less digits than its factorization.

251163708491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 422242.

The product of its (nonzero) digits is 362880, while the sum is 47.

The spelling of 251163708491 in words is "two hundred fifty-one billion, one hundred sixty-three million, seven hundred eight thousand, four hundred ninety-one".