76731872555521 has 4 divisors (see below), whose sum is σ = 76748996387844. Its totient is φ = 76714748723200.

The previous prime is 76731872555461. The next prime is 76731872555543. The reversal of 76731872555521 is 12555527813767.

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 49060064395521 + 27671808160000 = 7004289^2 + 5260400^2 .

It is a cyclic number.

It is not a de Polignac number, because 76731872555521 - 2³¹ = 76729725071873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (76731872550521) 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, 8561909440 + ... + 8561918401.

It is an arithmetic number, because the mean of its divisors is an integer number (19187249096961).

Almost surely, 2^{76731872555521} is an apocalyptic number.

It is an amenable number.

76731872555521 is a deficient number, since it is larger than the sum of its proper divisors (17123832323).

76731872555521 is a wasteful number, since it uses less digits than its factorization.

76731872555521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17123832322.

The product of its digits is 123480000, while the sum is 64.

The spelling of 76731872555521 in words is "seventy-six trillion, seven hundred thirty-one billion, eight hundred seventy-two million, five hundred fifty-five thousand, five hundred twenty-one".