251615120 has 20 divisors (see below), whose sum is σ = 585005340. Its totient is φ = 100646016.

The previous prime is 251615087. The next prime is 251615123. The reversal of 251615120 is 21516152.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 29724304 + 221890816 = 5452^2 + 14896^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-2 number, since 2×251615120² = 126620337225228800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (251615123) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1572515 + ... + 1572674.

It is an arithmetic number, because the mean of its divisors is an integer number (29250267).

Almost surely, 2^251615120 is an apocalyptic number.

251615120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

251615120 is an abundant number, since it is smaller than the sum of its proper divisors (333390220).

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

251615120 is a wasteful number, since it uses less digits than its factorization.

251615120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3145202 (or 3145196 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 23.

The square root of 251615120 is about 15862.3806536093. The cubic root of 251615120 is about 631.3142297157.

The spelling of 251615120 in words is "two hundred fifty-one million, six hundred fifteen thousand, one hundred twenty".