77797920 has 48 divisors (see below), whose sum is σ = 245064960. Its totient is φ = 20745984.

The previous prime is 77797919. The next prime is 77797949. The reversal of 77797920 is 2979777.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 77797920.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 80560 + ... + 81519.

It is an arithmetic number, because the mean of its divisors is an integer number (5105520).

Almost surely, 2^77797920 is an apocalyptic number.

It is an amenable number.

77797920 is an abundant number, since it is smaller than the sum of its proper divisors (167267040).

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

77797920 is a wasteful number, since it uses less digits than its factorization.

77797920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162097 (or 162089 counting only the distinct ones).

The product of its (nonzero) digits is 388962, while the sum is 48.

The square root of 77797920 is about 8820.3129196191. The cubic root of 77797920 is about 426.8965666394.

The spelling of 77797920 in words is "seventy-seven million, seven hundred ninety-seven thousand, nine hundred twenty".