251515242 has 24 divisors (see below), whose sum is σ = 594491040. Its totient is φ = 76216680.

The previous prime is 251515177. The next prime is 251515273. The reversal of 251515242 is 242515152.

251515242 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 634942 + ... + 635337.

It is an arithmetic number, because the mean of its divisors is an integer number (24770460).

Almost surely, 2^251515242 is an apocalyptic number.

251515242 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

251515242 is an abundant number, since it is smaller than the sum of its proper divisors (342975798).

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

251515242 is a wasteful number, since it uses less digits than its factorization.

251515242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1270298 (or 1270295 counting only the distinct ones).

The product of its digits is 4000, while the sum is 27.

The square root of 251515242 is about 15859.2320747254. The cubic root of 251515242 is about 631.2306857862.

The spelling of 251515242 in words is "two hundred fifty-one million, five hundred fifteen thousand, two hundred forty-two".