646785670 has 8 divisors (see below), whose sum is σ = 1164214224. Its totient is φ = 258714264.

The previous prime is 646785589. The next prime is 646785679. The reversal of 646785670 is 76587646.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646785679) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32339274 + ... + 32339293.

It is an arithmetic number, because the mean of its divisors is an integer number (145526778).

Almost surely, 2^646785670 is an apocalyptic number.

646785670 is a deficient number, since it is larger than the sum of its proper divisors (517428554).

646785670 is a wasteful number, since it uses less digits than its factorization.

646785670 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64678574.

The product of its (nonzero) digits is 1693440, while the sum is 49.

The square root of 646785670 is about 25431.9812440950. The cubic root of 646785670 is about 864.8088588320.

The spelling of 646785670 in words is "six hundred forty-six million, seven hundred eighty-five thousand, six hundred seventy".