251163601920 has 1056 divisors, whose sum is σ = 1101404169216. Its totient is φ = 51403161600.

The previous prime is 251163601877. The next prime is 251163601921. The reversal of 251163601920 is 29106361152.

251163601920 is a `hidden beast` number, since 2 + 5 + 1 + 1 + 636 + 0 + 19 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1056).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (251163601921) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 251918862 + ... + 251919858.

Almost surely, 2^251163601920 is an apocalyptic number.

251163601920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 251163601920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (550702084608).

251163601920 is an abundant number, since it is smaller than the sum of its proper divisors (850240567296).

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

251163601920 is a wasteful number, since it uses less digits than its factorization.

251163601920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1117 (or 1096 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The spelling of 251163601920 in words is "two hundred fifty-one billion, one hundred sixty-three million, six hundred one thousand, nine hundred twenty".