51550665660 has 72 divisors (see below), whose sum is σ = 168398848800. Its totient is φ = 12689394048.

The previous prime is 51550665599. The next prime is 51550665679. The reversal of 51550665660 is 6656605515.

It is a super-2 number, since 2×51550665660² (a number of 22 digits) contains 22 as substring.

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

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11012760 + ... + 11017439.

It is an arithmetic number, because the mean of its divisors is an integer number (2338872900).

Almost surely, 2^51550665660 is an apocalyptic number.

It is an amenable number.

51550665660 is an abundant number, since it is smaller than the sum of its proper divisors (116848183140).

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

51550665660 is a wasteful number, since it uses less digits than its factorization.

51550665660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22030227 (or 22030222 counting only the distinct ones).

The product of its (nonzero) digits is 810000, while the sum is 45.

The spelling of 51550665660 in words is "fifty-one billion, five hundred fifty million, six hundred sixty-five thousand, six hundred sixty".