51115506651 has 16 divisors (see below), whose sum is σ = 82610920320. Its totient is φ = 30979094760.

The previous prime is 51115506647. The next prime is 51115506667. The reversal of 51115506651 is 15660551115.

It is a happy number.

51115506651 is a `hidden beast` number, since 51 + 1 + 1 + 550 + 6 + 6 + 51 = 666.

It is not a de Polignac number, because 51115506651 - 2² = 51115506647 is a prime.

It is a super-2 number, since 2×51115506651² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (51115506601) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 86052745 + ... + 86053338.

It is an arithmetic number, because the mean of its divisors is an integer number (5163182520).

Almost surely, 2^51115506651 is an apocalyptic number.

51115506651 is a deficient number, since it is larger than the sum of its proper divisors (31495413669).

51115506651 is a wasteful number, since it uses less digits than its factorization.

51115506651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172106103 (or 172106097 counting only the distinct ones).

The product of its (nonzero) digits is 22500, while the sum is 36.

The spelling of 51115506651 in words is "fifty-one billion, one hundred fifteen million, five hundred six thousand, six hundred fifty-one".