76887744921 has 24 divisors (see below), whose sum is σ = 123727411080. Its totient is φ = 45683963136.

The previous prime is 76887744917. The next prime is 76887744929. The reversal of 76887744921 is 12944778867.

76887744921 is a `hidden beast` number, since 7 + 68 + 87 + 7 + 4 + 492 + 1 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 5574712896 + 71313032025 = 74664^2 + 267045^2 .

It is not a de Polignac number, because 76887744921 - 2² = 76887744917 is a prime.

It is a super-2 number, since 2×76887744921² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (76887744929) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11326956 + ... + 11333741.

It is an arithmetic number, because the mean of its divisors is an integer number (5155308795).

Almost surely, 2^76887744921 is an apocalyptic number.

It is an amenable number.

76887744921 is a deficient number, since it is larger than the sum of its proper divisors (46839666159).

76887744921 is a wasteful number, since it uses less digits than its factorization.

76887744921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22660745 (or 22660742 counting only the distinct ones).

The product of its digits is 37933056, while the sum is 63.

The spelling of 76887744921 in words is "seventy-six billion, eight hundred eighty-seven million, seven hundred forty-four thousand, nine hundred twenty-one".