251520325617 has 12 divisors (see below), whose sum is σ = 368619320720. Its totient is φ = 152436560760.

The previous prime is 251520325597. The next prime is 251520325631. The reversal of 251520325617 is 716523025152.

It is not a de Polignac number, because 251520325617 - 2¹⁴ = 251520309233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (251520325817) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 346446367 + ... + 346447092.

Almost surely, 2^251520325617 is an apocalyptic number.

It is an amenable number.

251520325617 is a deficient number, since it is larger than the sum of its proper divisors (117098995103).

251520325617 is a wasteful number, since it uses less digits than its factorization.

251520325617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 692893484 (or 692893473 counting only the distinct ones).

The product of its (nonzero) digits is 126000, while the sum is 39.

The spelling of 251520325617 in words is "two hundred fifty-one billion, five hundred twenty million, three hundred twenty-five thousand, six hundred seventeen".