251332345540 has 24 divisors (see below), whose sum is σ = 558844863192. Its totient is φ = 94619235840.

The previous prime is 251332345499. The next prime is 251332345549. The reversal of 251332345540 is 45543233152.

It can be written as a sum of positive squares in 4 ways, for example, as 59220195904 + 192112149636 = 243352^2 + 438306^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 251332345540.

It is not an unprimeable number, because it can be changed into a prime (251332345549) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 369606051 + ... + 369606730.

It is an arithmetic number, because the mean of its divisors is an integer number (23285202633).

Almost surely, 2^251332345540 is an apocalyptic number.

251332345540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

251332345540 is an abundant number, since it is smaller than the sum of its proper divisors (307512517652).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

251332345540 is a wasteful number, since it uses less digits than its factorization.

251332345540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 739212807 (or 739212805 counting only the distinct ones).

The product of its (nonzero) digits is 216000, while the sum is 37.

Adding to 251332345540 its reverse (45543233152), we get a palindrome (296875578692).

The spelling of 251332345540 in words is "two hundred fifty-one billion, three hundred thirty-two million, three hundred forty-five thousand, five hundred forty".