866185944 has 64 divisors (see below), whose sum is σ = 2356163040. Its totient is φ = 263761920.

The previous prime is 866185897. The next prime is 866185961. The reversal of 866185944 is 449581668.

866185944 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×866185944² = 1500556179166342272, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15954 + ... + 44574.

Almost surely, 2^866185944 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 866185944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1178081520).

866185944 is an abundant number, since it is smaller than the sum of its proper divisors (1489977096).

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

866185944 is a wasteful number, since it uses less digits than its factorization.

866185944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28740 (or 28736 counting only the distinct ones).

The product of its digits is 1658880, while the sum is 51.

The square root of 866185944 is about 29431.0370867219. The cubic root of 866185944 is about 953.2431884814.

The spelling of 866185944 in words is "eight hundred sixty-six million, one hundred eighty-five thousand, nine hundred forty-four".