977666555421 has 32 divisors (see below), whose sum is σ = 1459036782720. Its totient is φ = 647003814912.

The previous prime is 977666555413. The next prime is 977666555471. The reversal of 977666555421 is 124555666779.

It is a happy number.

It is not a de Polignac number, because 977666555421 - 2³ = 977666555413 is a prime.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (977666555401) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2148861 + ... + 2563773.

It is an arithmetic number, because the mean of its divisors is an integer number (45594899460).

Almost surely, 2^977666555421 is an apocalyptic number.

It is an amenable number.

977666555421 is a deficient number, since it is larger than the sum of its proper divisors (481370227299).

977666555421 is a wasteful number, since it uses less digits than its factorization.

977666555421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 415562 (or 415556 counting only the distinct ones).

The product of its digits is 95256000, while the sum is 63.

The spelling of 977666555421 in words is "nine hundred seventy-seven billion, six hundred sixty-six million, five hundred fifty-five thousand, four hundred twenty-one".