251221252121140 has 96 divisors (see below), whose sum is σ = 603196958972160. Its totient is φ = 86095015824384.

The previous prime is 251221252121107. The next prime is 251221252121201. The reversal of 251221252121140 is 41121252122152.

It is a super-2 number, since 2×251221252121140² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3184450816 + ... + 3184529704.

It is an arithmetic number, because the mean of its divisors is an integer number (6283301655960).

Almost surely, 2^{251221252121140} is an apocalyptic number.

251221252121140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

251221252121140 is an abundant number, since it is smaller than the sum of its proper divisors (351975706851020).

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

251221252121140 is a wasteful number, since it uses less digits than its factorization.

251221252121140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88649 (or 88647 counting only the distinct ones).

The product of its (nonzero) digits is 6400, while the sum is 31.

The spelling of 251221252121140 in words is "two hundred fifty-one trillion, two hundred twenty-one billion, two hundred fifty-two million, one hundred twenty-one thousand, one hundred forty".