251136620240 has 80 divisors (see below), whose sum is σ = 645036929280. Its totient is φ = 90166402560.

The previous prime is 251136620233. The next prime is 251136620351. The reversal of 251136620240 is 42026631152.

It is a tau number, because it is divible by the number of its divisors (80).

It is a junction number, because it is equal to n+sod(n) for n = 251136620197 and 251136620206.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1736699 + ... + 1875738.

It is an arithmetic number, because the mean of its divisors is an integer number (8062961616).

Almost surely, 2^251136620240 is an apocalyptic number.

251136620240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

251136620240 is an abundant number, since it is smaller than the sum of its proper divisors (393900309040).

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

251136620240 is a wasteful number, since it uses less digits than its factorization.

251136620240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3612540 (or 3612534 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 32.

The spelling of 251136620240 in words is "two hundred fifty-one billion, one hundred thirty-six million, six hundred twenty thousand, two hundred forty".