51916795884721 has 4 divisors (see below), whose sum is σ = 53319952530292. Its totient is φ = 50513639239152.

The previous prime is 51916795884691. The next prime is 51916795884739. The reversal of 51916795884721 is 12748859761915.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 27659594859121 + 24257201025600 = 5259239^2 + 4925160^2 .

It is a cyclic number.

It is not a de Polignac number, because 51916795884721 - 2⁷ = 51916795884593 is a prime.

It is a super-2 number, since 2×51916795884721² (a number of 28 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (51916795884761) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 701578322730 + ... + 701578322803.

It is an arithmetic number, because the mean of its divisors is an integer number (13329988132573).

Almost surely, 2^{51916795884721} is an apocalyptic number.

It is an amenable number.

51916795884721 is a deficient number, since it is larger than the sum of its proper divisors (1403156645571).

51916795884721 is a wasteful number, since it uses less digits than its factorization.

51916795884721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1403156645570.

The product of its digits is 304819200, while the sum is 73.

The spelling of 51916795884721 in words is "fifty-one trillion, nine hundred sixteen billion, seven hundred ninety-five million, eight hundred eighty-four thousand, seven hundred twenty-one".