51686365172 has 24 divisors (see below), whose sum is σ = 97459089000. Its totient is φ = 23842958976.

The previous prime is 51686365117. The next prime is 51686365177. The reversal of 51686365172 is 27156368615.

It can be written as a sum of positive squares in 4 ways, for example, as 105596176 + 51580768996 = 10276^2 + 227114^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 51686365172.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51686365177) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 153647 + ... + 356342.

It is an arithmetic number, because the mean of its divisors is an integer number (4060795375).

Almost surely, 2^51686365172 is an apocalyptic number.

51686365172 is a gapful number since it is divisible by the number (52) formed by its first and last digit.

It is an amenable number.

51686365172 is a deficient number, since it is larger than the sum of its proper divisors (45772723828).

51686365172 is a wasteful number, since it uses less digits than its factorization.

51686365172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 511955 (or 511953 counting only the distinct ones).

The product of its digits is 1814400, while the sum is 50.

The spelling of 51686365172 in words is "fifty-one billion, six hundred eighty-six million, three hundred sixty-five thousand, one hundred seventy-two".