77679313921 has 12 divisors (see below), whose sum is σ = 85620931200. Its totient is φ = 70420812440.

The previous prime is 77679313897. The next prime is 77679313927. The reversal of 77679313921 is 12931397677.

It is a de Polignac number, because none of the positive numbers 2^k-77679313921 is a prime.

It is a super-2 number, since 2×77679313921² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77679313927) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 850681 + ... + 937558.

It is an arithmetic number, because the mean of its divisors is an integer number (7135077600).

Almost surely, 2^77679313921 is an apocalyptic number.

It is an amenable number.

77679313921 is a deficient number, since it is larger than the sum of its proper divisors (7941617279).

77679313921 is a wasteful number, since it uses less digits than its factorization.

77679313921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1788620 (or 1788609 counting only the distinct ones).

The product of its digits is 3000564, while the sum is 55.

The spelling of 77679313921 in words is "seventy-seven billion, six hundred seventy-nine million, three hundred thirteen thousand, nine hundred twenty-one".