251959218240 has 56 divisors (see below), whose sum is σ = 799970520960. Its totient is φ = 67189124608.

The previous prime is 251959218239. The next prime is 251959218263. The reversal of 251959218240 is 42812959152.

It is a super-2 number, since 2×251959218240² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 251959218240.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 131227800 + ... + 131229719.

Almost surely, 2^251959218240 is an apocalyptic number.

251959218240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

251959218240 is an abundant number, since it is smaller than the sum of its proper divisors (548011302720).

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

251959218240 is a wasteful number, since it uses less digits than its factorization.

251959218240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 262457539 (or 262457529 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 48.

The spelling of 251959218240 in words is "two hundred fifty-one billion, nine hundred fifty-nine million, two hundred eighteen thousand, two hundred forty".