51531347520 has 84 divisors (see below), whose sum is σ = 177246373980. Its totient is φ = 13741691904.

The previous prime is 51531347519. The next prime is 51531347537. The reversal of 51531347520 is 2574313515.

51531347520 is a `hidden beast` number, since 5 + 1 + 531 + 34 + 75 + 20 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 28807593984 + 22723753536 = 169728^2 + 150744^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

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, 8943535 + ... + 8949294.

Almost surely, 2^51531347520 is an apocalyptic number.

It is an amenable number.

51531347520 is an abundant number, since it is smaller than the sum of its proper divisors (125715026460).

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

51531347520 is a wasteful number, since it uses less digits than its factorization.

51531347520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17892852 (or 17892839 counting only the distinct ones).

The product of its (nonzero) digits is 63000, while the sum is 36.

The spelling of 51531347520 in words is "fifty-one billion, five hundred thirty-one million, three hundred forty-seven thousand, five hundred twenty".