51261599916 has 18 divisors (see below), whose sum is σ = 129577933212. Its totient is φ = 17087199960.

The previous prime is 51261599903. The next prime is 51261600041. The reversal of 51261599916 is 61999516215.

51261599916 is a `hidden beast` number, since 5 + 1 + 2 + 615 + 9 + 9 + 9 + 16 = 666.

It is a tau number, because it is divible by the number of its divisors (18).

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 5 ways as a sum of consecutive naturals, for example, 711966630 + ... + 711966701.

Almost surely, 2^51261599916 is an apocalyptic number.

It is an amenable number.

51261599916 is an abundant number, since it is smaller than the sum of its proper divisors (78316333296).

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

51261599916 is a wasteful number, since it uses less digits than its factorization.

51261599916 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1423933341 (or 1423933336 counting only the distinct ones).

The product of its digits is 1312200, while the sum is 54.

The spelling of 51261599916 in words is "fifty-one billion, two hundred sixty-one million, five hundred ninety-nine thousand, nine hundred sixteen".