866756979520 has 28 divisors (see below), whose sum is σ = 2063965058244. Its totient is φ = 346702791680.

The previous prime is 866756979511. The next prime is 866756979521. The reversal of 866756979520 is 25979657668.

It can be written as a sum of positive squares in 2 ways, for example, as 166013872704 + 700743106816 = 407448^2 + 837104^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 866756979520.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866756979521) 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, 1354307461 + ... + 1354308100.

Almost surely, 2^866756979520 is an apocalyptic number.

866756979520 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

866756979520 is an abundant number, since it is smaller than the sum of its proper divisors (1197208078724).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

866756979520 is a wasteful number, since it uses less digits than its factorization.

866756979520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2708615578 (or 2708615568 counting only the distinct ones).

The product of its (nonzero) digits is 342921600, while the sum is 70.

The spelling of 866756979520 in words is "eight hundred sixty-six billion, seven hundred fifty-six million, nine hundred seventy-nine thousand, five hundred twenty".