51661651116164 has 24 divisors (see below), whose sum is σ = 95933649247128. Its totient is φ = 24258629066240.

The previous prime is 51661651116161. The next prime is 51661651116169. The reversal of 51661651116164 is 46161115616615.

It can be written as a sum of positive squares in 4 ways, for example, as 2017536160000 + 49644114956164 = 1420400^2 + 7045858^2 .

It is not an unprimeable number, because it can be changed into a prime (51661651116161) 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, 823970999 + ... + 824033694.

It is an arithmetic number, because the mean of its divisors is an integer number (3997235385297).

Almost surely, 2^{51661651116164} is an apocalyptic number.

It is an amenable number.

51661651116164 is a deficient number, since it is larger than the sum of its proper divisors (44271998130964).

51661651116164 is a wasteful number, since it uses less digits than its factorization.

51661651116164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1648005175 (or 1648005173 counting only the distinct ones).

The product of its digits is 777600, while the sum is 50.

The spelling of 51661651116164 in words is "fifty-one trillion, six hundred sixty-one billion, six hundred fifty-one million, one hundred sixteen thousand, one hundred sixty-four".