51206907816 has 192 divisors, whose sum is σ = 154446289920. Its totient is φ = 15252756480.

The previous prime is 51206907793. The next prime is 51206907823. The reversal of 51206907816 is 61870960215.

51206907816 is a `hidden beast` number, since 512 + 0 + 69 + 0 + 78 + 1 + 6 = 666.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1998301 + ... + 2023763.

It is an arithmetic number, because the mean of its divisors is an integer number (804407760).

Almost surely, 2^51206907816 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51206907816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (77223144960).

51206907816 is an abundant number, since it is smaller than the sum of its proper divisors (103239382104).

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

51206907816 is a wasteful number, since it uses less digits than its factorization.

51206907816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25576 (or 25569 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 45.

The spelling of 51206907816 in words is "fifty-one billion, two hundred six million, nine hundred seven thousand, eight hundred sixteen".