77918720 has 80 divisors (see below), whose sum is σ = 203879808. Its totient is φ = 28323840.

The previous prime is 77918719. The next prime is 77918807. The reversal of 77918720 is 2781977.

It is a tau number, because it is divible by the number of its divisors (80).

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, 26777 + ... + 29543.

Almost surely, 2^77918720 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77918720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101939904).

77918720 is an abundant number, since it is smaller than the sum of its proper divisors (125961088).

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

77918720 is a wasteful number, since it uses less digits than its factorization.

77918720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2801 (or 2785 counting only the distinct ones).

The product of its (nonzero) digits is 49392, while the sum is 41.

The square root of 77918720 is about 8827.1580930671. The cubic root of 77918720 is about 427.1174056074.

The spelling of 77918720 in words is "seventy-seven million, nine hundred eighteen thousand, seven hundred twenty".