77907840 has 64 divisors (see below), whose sum is σ = 248337360. Its totient is φ = 20774912.

The previous prime is 77907799. The next prime is 77907857. The reversal of 77907840 is 4870977.

It is a tau number, because it is divible by the number of its divisors (64).

It is a junction number, because it is equal to n+sod(n) for n = 77907792 and 77907801.

It is a congruent number.

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, 18369 + ... + 22208.

Almost surely, 2^77907840 is an apocalyptic number.

It is an amenable number.

77907840 is an abundant number, since it is smaller than the sum of its proper divisors (170429520).

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

77907840 is a wasteful number, since it uses less digits than its factorization.

77907840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40599 (or 40587 counting only the distinct ones).

The product of its (nonzero) digits is 98784, while the sum is 42.

The square root of 77907840 is about 8826.5417916645. The cubic root of 77907840 is about 427.0975248321.

The spelling of 77907840 in words is "seventy-seven million, nine hundred seven thousand, eight hundred forty".