77921880 has 64 divisors (see below), whose sum is σ = 247523040. Its totient is φ = 19556352.

The previous prime is 77921873. The next prime is 77921881. The reversal of 77921880 is 8812977.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77921881) 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, 17059 + ... + 21138.

Almost surely, 2^77921880 is an apocalyptic number.

It is an amenable number.

77921880 is an abundant number, since it is smaller than the sum of its proper divisors (169601160).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

77921880 is a wasteful number, since it uses less digits than its factorization.

77921880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38228 (or 38224 counting only the distinct ones).

The product of its (nonzero) digits is 56448, while the sum is 42.

The square root of 77921880 is about 8827.3370843080. The cubic root of 77921880 is about 427.1231794563.

The spelling of 77921880 in words is "seventy-seven million, nine hundred twenty-one thousand, eight hundred eighty".