51521131002400 has 72 divisors (see below), whose sum is σ = 125822326832244. Its totient is φ = 20600855347200.

The previous prime is 51521131002373. The next prime is 51521131002413. The reversal of 51521131002400 is 420013112515.

It can be written as a sum of positive squares in 6 ways, for example, as 46590617335824 + 4930513666576 = 6825732^2 + 2220476^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

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, 9698641 + ... + 14039440.

Almost surely, 2^{51521131002400} is an apocalyptic number.

51521131002400 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

It is an amenable number.

51521131002400 is an abundant number, since it is smaller than the sum of its proper divisors (74301195829844).

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

51521131002400 is a wasteful number, since it uses less digits than its factorization.

51521131002400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23740814 (or 23740801 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 25.

Adding to 51521131002400 its reverse (420013112515), we get a palindrome (51941144114915).

The spelling of 51521131002400 in words is "fifty-one trillion, five hundred twenty-one billion, one hundred thirty-one million, two thousand, four hundred".