865990656 has 96 divisors (see below), whose sum is σ = 2565435600. Its totient is φ = 288645120.

The previous prime is 865990603. The next prime is 865990667. The reversal of 865990656 is 656099568.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47466 + ... + 63126.

Almost surely, 2^865990656 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 865990656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1282717800).

865990656 is an abundant number, since it is smaller than the sum of its proper divisors (1699444944).

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

865990656 is a wasteful number, since it uses less digits than its factorization.

865990656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15692 (or 15666 counting only the distinct ones).

The product of its (nonzero) digits is 3499200, while the sum is 54.

The square root of 865990656 is about 29427.7191776733. The cubic root of 865990656 is about 953.1715445313.

The spelling of 865990656 in words is "eight hundred sixty-five million, nine hundred ninety thousand, six hundred fifty-six".