866721156824 has 16 divisors (see below), whose sum is σ = 1625282610720. Its totient is φ = 433312460640.

The previous prime is 866721156809. The next prime is 866721156881. The reversal of 866721156824 is 428651127668.

It is a self number, because there is not a number n which added to its sum of digits gives 866721156824.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5938112 + ... + 6082319.

It is an arithmetic number, because the mean of its divisors is an integer number (101580163170).

Almost surely, 2^866721156824 is an apocalyptic number.

It is an amenable number.

866721156824 is a deficient number, since it is larger than the sum of its proper divisors (758561453896).

866721156824 is a wasteful number, since it uses less digits than its factorization.

866721156824 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12029450 (or 12029446 counting only the distinct ones).

The product of its digits is 7741440, while the sum is 56.

The spelling of 866721156824 in words is "eight hundred sixty-six billion, seven hundred twenty-one million, one hundred fifty-six thousand, eight hundred twenty-four".