866189945825 has 24 divisors (see below), whose sum is σ = 1094489878968. Its totient is φ = 679784967680.

The previous prime is 866189945779. The next prime is 866189945851. The reversal of 866189945825 is 528549981668.

It can be written as a sum of positive squares in 12 ways, for example, as 8187897169 + 858002048656 = 90487^2 + 926284^2 .

It is not a de Polignac number, because 866189945825 - 2³⁸ = 591312038881 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10682837 + ... + 10763613.

It is an arithmetic number, because the mean of its divisors is an integer number (45603744957).

Almost surely, 2^866189945825 is an apocalyptic number.

It is an amenable number.

866189945825 is a deficient number, since it is larger than the sum of its proper divisors (228299933143).

866189945825 is a wasteful number, since it uses less digits than its factorization.

866189945825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88933 (or 88928 counting only the distinct ones).

The product of its digits is 298598400, while the sum is 71.

The spelling of 866189945825 in words is "eight hundred sixty-six billion, one hundred eighty-nine million, nine hundred forty-five thousand, eight hundred twenty-five".