977988966781 has 4 divisors (see below), whose sum is σ = 980110418364. Its totient is φ = 975867515200.

The previous prime is 977988966641. The next prime is 977988966847. The reversal of 977988966781 is 187669889779.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 622970811225 + 355018155556 = 789285^2 + 595834^2 .

It is a cyclic number.

It is not a de Polignac number, because 977988966781 - 2³⁵ = 943629228413 is a prime.

It is a super-2 number, since 2×977988966781² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (977988966181) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1060725100 + ... + 1060726021.

It is an arithmetic number, because the mean of its divisors is an integer number (245027604591).

Almost surely, 2^977988966781 is an apocalyptic number.

It is an amenable number.

977988966781 is a deficient number, since it is larger than the sum of its proper divisors (2121451583).

977988966781 is a wasteful number, since it uses less digits than its factorization.

977988966781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2121451582.

The product of its digits is 4608866304, while the sum is 85.

The spelling of 977988966781 in words is "nine hundred seventy-seven billion, nine hundred eighty-eight million, nine hundred sixty-six thousand, seven hundred eighty-one".