977643639 has 24 divisors (see below), whose sum is σ = 1646829600. Its totient is φ = 558651744.

The previous prime is 977643619. The next prime is 977643673. The reversal of 977643639 is 936346779.

It is not a de Polignac number, because 977643639 - 2¹⁷ = 977512567 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (977643619) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 155262 + ... + 161435.

It is an arithmetic number, because the mean of its divisors is an integer number (68617900).

Almost surely, 2^977643639 is an apocalyptic number.

977643639 is a deficient number, since it is larger than the sum of its proper divisors (669185961).

977643639 is a wasteful number, since it uses less digits than its factorization.

977643639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 316724 (or 316707 counting only the distinct ones).

The product of its digits is 5143824, while the sum is 54.

The square root of 977643639 is about 31267.2934389915. The cubic root of 977643639 is about 992.4916453729.

The spelling of 977643639 in words is "nine hundred seventy-seven million, six hundred forty-three thousand, six hundred thirty-nine".