51767655665 has 12 divisors (see below), whose sum is σ = 68281966452. Its totient is φ = 37649203680.

The previous prime is 51767655649. The next prime is 51767655677. The reversal of 51767655665 is 56655676715.

It can be written as a sum of positive squares in 2 ways, for example, as 14197199104 + 37570456561 = 119152^2 + 193831^2 .

It is not a de Polignac number, because 51767655665 - 2⁴ = 51767655649 is a prime.

It is a Duffinian 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, 42782582 + ... + 42783791.

It is an arithmetic number, because the mean of its divisors is an integer number (5690163871).

Almost surely, 2^51767655665 is an apocalyptic number.

51767655665 is a gapful number since it is divisible by the number (55) formed by its first and last digit.

It is an amenable number.

51767655665 is a deficient number, since it is larger than the sum of its proper divisors (16514310787).

51767655665 is a wasteful number, since it uses less digits than its factorization.

51767655665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85566400 (or 85566389 counting only the distinct ones).

The product of its digits is 39690000, while the sum is 59.

The spelling of 51767655665 in words is "fifty-one billion, seven hundred sixty-seven million, six hundred fifty-five thousand, six hundred sixty-five".