251211551020100 has 72 divisors (see below), whose sum is σ = 620542177633728. Its totient is φ = 87377930780800.

The previous prime is 251211551020043. The next prime is 251211551020117. The reversal of 251211551020100 is 1020155112152.

It is a self number, because there is not a number n which added to its sum of digits gives 251211551020100.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4964629859 + ... + 4964680458.

It is an arithmetic number, because the mean of its divisors is an integer number (8618641356024).

Almost surely, 2^{251211551020100} is an apocalyptic number.

251211551020100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

251211551020100 is an abundant number, since it is smaller than the sum of its proper divisors (369330626613628).

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

251211551020100 is a wasteful number, since it uses less digits than its factorization.

251211551020100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9929310365 (or 9929310358 counting only the distinct ones).

The product of its (nonzero) digits is 1000, while the sum is 26.

The spelling of 251211551020100 in words is "two hundred fifty-one trillion, two hundred eleven billion, five hundred fifty-one million, twenty thousand, one hundred".