77922640 has 20 divisors (see below), whose sum is σ = 181170324. Its totient is φ = 31169024.

The previous prime is 77922631. The next prime is 77922659. The reversal of 77922640 is 4622977.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 56430144 + 21492496 = 7512^2 + 4636^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a self number, because there is not a number n which added to its sum of digits gives 77922640.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 486937 + ... + 487096.

Almost surely, 2^77922640 is an apocalyptic number.

It is an amenable number.

77922640 is an abundant number, since it is smaller than the sum of its proper divisors (103247684).

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

77922640 is a wasteful number, since it uses less digits than its factorization.

77922640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 974046 (or 974040 counting only the distinct ones).

The product of its (nonzero) digits is 42336, while the sum is 37.

The square root of 77922640 is about 8827.3801322929. The cubic root of 77922640 is about 427.1245680803.

The spelling of 77922640 in words is "seventy-seven million, nine hundred twenty-two thousand, six hundred forty".