51313191618420 has 120 divisors (see below), whose sum is σ = 160975462725000. Its totient is φ = 13683170930688.

The previous prime is 51313191618349. The next prime is 51313191618457. The reversal of 51313191618420 is 2481619131315.

51313191618420 is a `hidden beast` number, since 5 + 1 + 3 + 1 + 3 + 1 + 9 + 1 + 618 + 4 + 20 = 666.

51313191618420 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 3433379231844 + 47879812386576 = 1852938^2 + 6919524^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 67025956 + ... + 67787204.

It is an arithmetic number, because the mean of its divisors is an integer number (1341462189375).

Almost surely, 2^{51313191618420} is an apocalyptic number.

It is an amenable number.

51313191618420 is an abundant number, since it is smaller than the sum of its proper divisors (109662271106580).

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

51313191618420 is a wasteful number, since it uses less digits than its factorization.

51313191618420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 802879 (or 802868 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 45.

The spelling of 51313191618420 in words is "fifty-one trillion, three hundred thirteen billion, one hundred ninety-one million, six hundred eighteen thousand, four hundred twenty".