251981912484 has 27 divisors (see below), whose sum is σ = 636961892203. Its totient is φ = 83992966872.

The previous prime is 251981912473. The next prime is 251981912503. The reversal of 251981912484 is 484219189152.

The square root of 251981912484 is 501978.

It is a perfect power (a square), and thus also a powerful number.

251981912484 is a `hidden beast` number, since 2 + 51 + 98 + 19 + 12 + 484 = 666.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 251981912484.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 2970037 + ... + 3053699.

Almost surely, 2^251981912484 is an apocalyptic number.

251981912484 is the 501978-th square number.

It is an amenable number.

251981912484 is an abundant number, since it is smaller than the sum of its proper divisors (384979979719).

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

251981912484 is an frugal number, since it uses more digits than its factorization.

251981912484 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167336 (or 83668 counting only the distinct ones).

The product of its digits is 1658880, while the sum is 54.

The spelling of 251981912484 in words is "two hundred fifty-one billion, nine hundred eighty-one million, nine hundred twelve thousand, four hundred eighty-four".