51571218816 has 96 divisors (see below), whose sum is σ = 159817104720. Its totient is φ = 15868062720.

The previous prime is 51571218733. The next prime is 51571218821. The reversal of 51571218816 is 61881217515.

51571218816 is a `hidden beast` number, since 51 + 571 + 2 + 18 + 8 + 16 = 666.

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

It is a super-2 number, since 2×51571218816² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

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, 1706820 + ... + 1736771.

Almost surely, 2^51571218816 is an apocalyptic number.

It is an amenable number.

51571218816 is an abundant number, since it is smaller than the sum of its proper divisors (108245885904).

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

51571218816 is a wasteful number, since it uses less digits than its factorization.

51571218816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3443624 (or 3443609 counting only the distinct ones).

The product of its digits is 134400, while the sum is 45.

The spelling of 51571218816 in words is "fifty-one billion, five hundred seventy-one million, two hundred eighteen thousand, eight hundred sixteen".