77711957921 has 16 divisors (see below), whose sum is σ = 85288460544. Its totient is φ = 70364458944.

The previous prime is 77711957909. The next prime is 77711957927. The reversal of 77711957921 is 12975911777.

It is not a de Polignac number, because 77711957921 - 2⁶ = 77711957857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77711957927) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3797900 + ... + 3818306.

It is an arithmetic number, because the mean of its divisors is an integer number (5330528784).

Almost surely, 2^77711957921 is an apocalyptic number.

It is an amenable number.

77711957921 is a deficient number, since it is larger than the sum of its proper divisors (7576502623).

77711957921 is a wasteful number, since it uses less digits than its factorization.

77711957921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26000.

The product of its digits is 1944810, while the sum is 56.

The spelling of 77711957921 in words is "seventy-seven billion, seven hundred eleven million, nine hundred fifty-seven thousand, nine hundred twenty-one".