77638972 has 12 divisors (see below), whose sum is σ = 137395440. Its totient is φ = 38383136.

The previous prime is 77638969. The next prime is 77638993. The reversal of 77638972 is 27983677.

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, 108688 + ... + 109399.

It is an arithmetic number, because the mean of its divisors is an integer number (11449620).

Almost surely, 2^77638972 is an apocalyptic number.

It is an amenable number.

77638972 is a deficient number, since it is larger than the sum of its proper divisors (59756468).

77638972 is a wasteful number, since it uses less digits than its factorization.

77638972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218180 (or 218178 counting only the distinct ones).

The product of its digits is 889056, while the sum is 49.

The square root of 77638972 is about 8811.2979747595. The cubic root of 77638972 is about 426.6056393292.

The spelling of 77638972 in words is "seventy-seven million, six hundred thirty-eight thousand, nine hundred seventy-two".