646138608 has 20 divisors (see below), whose sum is σ = 1669191528. Its totient is φ = 215379520.

The previous prime is 646138579. The next prime is 646138667. The reversal of 646138608 is 806831646.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 646138608.

It is a congruent number.

It is an unprimeable number.

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, 6730563 + ... + 6730658.

Almost surely, 2^646138608 is an apocalyptic number.

It is an amenable number.

646138608 is an abundant number, since it is smaller than the sum of its proper divisors (1023052920).

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

646138608 is a wasteful number, since it uses less digits than its factorization.

646138608 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13461232 (or 13461226 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 42.

The square root of 646138608 is about 25419.2566374393. The cubic root of 646138608 is about 864.5203698278.

The spelling of 646138608 in words is "six hundred forty-six million, one hundred thirty-eight thousand, six hundred eight".