869581552938921 has 20 divisors (see below), whose sum is σ = 1314655199187792. Its totient is φ = 572736444501528.

The previous prime is 869581552938907. The next prime is 869581552938947. The reversal of 869581552938921 is 129839255185968.

It is a happy number.

869581552938921 is a `hidden beast` number, since 8 + 6 + 9 + 5 + 8 + 1 + 5 + 529 + 3 + 89 + 2 + 1 = 666.

It is not a de Polignac number, because 869581552938921 - 2²⁵ = 869581519384489 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (81).

It is not an unprimeable number, because it can be changed into a prime (869581552938121) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 64672130191 + ... + 64672143636.

Almost surely, 2^{869581552938921} is an apocalyptic number.

869581552938921 is a gapful number since it is divisible by the number (81) formed by its first and last digit.

It is an amenable number.

869581552938921 is a deficient number, since it is larger than the sum of its proper divisors (445073646248871).

869581552938921 is a wasteful number, since it uses less digits than its factorization.

869581552938921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129344273922 (or 129344273913 counting only the distinct ones).

The product of its digits is 3359232000, while the sum is 81.

The spelling of 869581552938921 in words is "eight hundred sixty-nine trillion, five hundred eighty-one billion, five hundred fifty-two million, nine hundred thirty-eight thousand, nine hundred twenty-one".