866239921272 has 32 divisors (see below), whose sum is σ = 2362472513280. Its totient is φ = 262496945760.

The previous prime is 866239921249. The next prime is 866239921291. The reversal of 866239921272 is 272129932668.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1640605648 + ... + 1640606175.

It is an arithmetic number, because the mean of its divisors is an integer number (73827266040).

Almost surely, 2^866239921272 is an apocalyptic number.

It is an amenable number.

866239921272 is an abundant number, since it is smaller than the sum of its proper divisors (1496232592008).

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

866239921272 is a wasteful number, since it uses less digits than its factorization.

866239921272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3281211843 (or 3281211839 counting only the distinct ones).

The product of its digits is 7838208, while the sum is 57.

The spelling of 866239921272 in words is "eight hundred sixty-six billion, two hundred thirty-nine million, nine hundred twenty-one thousand, two hundred seventy-two".