646880865 has 32 divisors (see below), whose sum is σ = 1081589760. Its totient is φ = 329520576.

The previous prime is 646880851. The next prime is 646880867. The reversal of 646880865 is 568088646.

646880865 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 646880865 - 2²⁰ = 645832289 is a prime.

It is not an unprimeable number, because it can be changed into a prime (646880867) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 448816 + ... + 450254.

It is an arithmetic number, because the mean of its divisors is an integer number (33799680).

Almost surely, 2^646880865 is an apocalyptic number.

It is an amenable number.

646880865 is a deficient number, since it is larger than the sum of its proper divisors (434708895).

646880865 is a wasteful number, since it uses less digits than its factorization.

646880865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2773.

The product of its (nonzero) digits is 2211840, while the sum is 51.

The square root of 646880865 is about 25433.8527360681. The cubic root of 646880865 is about 864.8512847569.

The spelling of 646880865 in words is "six hundred forty-six million, eight hundred eighty thousand, eight hundred sixty-five".