251113254240 has 96 divisors (see below), whose sum is σ = 791562451680. Its totient is φ = 66916491264.

The previous prime is 251113254239. The next prime is 251113254253. The reversal of 251113254240 is 42452311152.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 251113254198 and 251113254207.

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, 502872 + ... + 868968.

It is an arithmetic number, because the mean of its divisors is an integer number (8245442205).

Almost surely, 2^251113254240 is an apocalyptic number.

251113254240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 251113254240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (395781225840).

251113254240 is an abundant number, since it is smaller than the sum of its proper divisors (540449197440).

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

251113254240 is a wasteful number, since it uses less digits than its factorization.

251113254240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 367544 (or 367536 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 30.

Adding to 251113254240 its reverse (42452311152), we get a palindrome (293565565392).

The spelling of 251113254240 in words is "two hundred fifty-one billion, one hundred thirteen million, two hundred fifty-four thousand, two hundred forty".