51656511651 has 4 divisors (see below), whose sum is σ = 68875348872. Its totient is φ = 34437674432.

The previous prime is 51656511539. The next prime is 51656511689. The reversal of 51656511651 is 15611565615.

51656511651 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 51656511651 - 2¹⁰ = 51656510627 is a prime.

It is not an unprimeable number, because it can be changed into a prime (51656511691) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8609418606 + ... + 8609418611.

It is an arithmetic number, because the mean of its divisors is an integer number (17218837218).

Almost surely, 2^51656511651 is an apocalyptic number.

51656511651 is a deficient number, since it is larger than the sum of its proper divisors (17218837221).

51656511651 is a wasteful number, since it uses less digits than its factorization.

51656511651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17218837220.

The product of its digits is 135000, while the sum is 42.

The spelling of 51656511651 in words is "fifty-one billion, six hundred fifty-six million, five hundred eleven thousand, six hundred fifty-one".