77661497936 has 80 divisors (see below), whose sum is σ = 173909369088. Its totient is φ = 33204019200.

The previous prime is 77661497929. The next prime is 77661497983. The reversal of 77661497936 is 63979416677.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5591096 + ... + 5604968.

Almost surely, 2^77661497936 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 77661497936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86954684544).

77661497936 is an abundant number, since it is smaller than the sum of its proper divisors (96247871152).

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

77661497936 is a wasteful number, since it uses less digits than its factorization.

77661497936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15780 (or 15774 counting only the distinct ones).

The product of its digits is 72013536, while the sum is 65.

The spelling of 77661497936 in words is "seventy-seven billion, six hundred sixty-one million, four hundred ninety-seven thousand, nine hundred thirty-six".