646943676 has 12 divisors (see below), whose sum is σ = 1509535272. Its totient is φ = 215647888.

The previous prime is 646943663. The next prime is 646943699. The reversal of 646943676 is 676349646.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×646943676² = 837072239832785952, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26955975 + ... + 26955998.

It is an arithmetic number, because the mean of its divisors is an integer number (125794606).

Almost surely, 2^646943676 is an apocalyptic number.

It is an amenable number.

646943676 is an abundant number, since it is smaller than the sum of its proper divisors (862591596).

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

646943676 is a wasteful number, since it uses less digits than its factorization.

646943676 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53911980 (or 53911978 counting only the distinct ones).

The product of its digits is 3919104, while the sum is 51.

The square root of 646943676 is about 25435.0874973923. The cubic root of 646943676 is about 864.8792756997.

The spelling of 646943676 in words is "six hundred forty-six million, nine hundred forty-three thousand, six hundred seventy-six".