977639661 has 12 divisors (see below), whose sum is σ = 1486469920. Its totient is φ = 617456520.

The previous prime is 977639657. The next prime is 977639693. The reversal of 977639661 is 166936779.

It is not a de Polignac number, because 977639661 - 2² = 977639657 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 977639598 and 977639607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (977639461) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2858425 + ... + 2858766.

Almost surely, 2^977639661 is an apocalyptic number.

It is an amenable number.

977639661 is a deficient number, since it is larger than the sum of its proper divisors (508830259).

977639661 is a wasteful number, since it uses less digits than its factorization.

977639661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5717216 (or 5717213 counting only the distinct ones).

The product of its digits is 2571912, while the sum is 54.

The square root of 977639661 is about 31267.2298261295. The cubic root of 977639661 is about 992.4902992324.

The spelling of 977639661 in words is "nine hundred seventy-seven million, six hundred thirty-nine thousand, six hundred sixty-one".