77697640 has 16 divisors (see below), whose sum is σ = 174819780. Its totient is φ = 31079040.

The previous prime is 77697637. The next prime is 77697671. The reversal of 77697640 is 4679677.

It can be written as a sum of positive squares in 2 ways, for example, as 64866916 + 12830724 = 8054^2 + 3582^2 .

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, 971181 + ... + 971260.

Almost surely, 2^77697640 is an apocalyptic number.

It is an amenable number.

77697640 is an abundant number, since it is smaller than the sum of its proper divisors (97122140).

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

77697640 is a wasteful number, since it uses less digits than its factorization.

77697640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1942452 (or 1942448 counting only the distinct ones).

The product of its (nonzero) digits is 444528, while the sum is 46.

The square root of 77697640 is about 8814.6264810257. The cubic root of 77697640 is about 426.7130673278.

The spelling of 77697640 in words is "seventy-seven million, six hundred ninety-seven thousand, six hundred forty".