51681332794729 has 135 divisors (see below), whose sum is σ = 62206100777415. Its totient is φ = 42930246284640.

The previous prime is 51681332794697. The next prime is 51681332794853. The reversal of 51681332794729 is 92749723318615.

The square root of 51681332794729 is 7188973.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 37256923784025 + 14424409010704 = 6103845^2 + 3797948^2 .

It is not a de Polignac number, because 51681332794729 - 2⁵ = 51681332794697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51681332734729) by changing a digit.

It is a polite number, since it can be written in 134 ways as a sum of consecutive naturals, for example, 875954793102 + ... + 875954793160.

Almost surely, 2^{51681332794729} is an apocalyptic number.

51681332794729 is a gapful number since it is divisible by the number (59) formed by its first and last digit.

51681332794729 is the 7188973-rd square number.

51681332794729 is the 3594487-th centered octagonal number.

It is an amenable number.

51681332794729 is a deficient number, since it is larger than the sum of its proper divisors (10524767982686).

51681332794729 is an frugal number, since it uses more digits than its factorization.

51681332794729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 306 (or 142 counting only the distinct ones).

The product of its digits is 137168640, while the sum is 67.

The spelling of 51681332794729 in words is "fifty-one trillion, six hundred eighty-one billion, three hundred thirty-two million, seven hundred ninety-four thousand, seven hundred twenty-nine".