646656436 has 12 divisors (see below), whose sum is σ = 1131924640. Its totient is φ = 323249400.

The previous prime is 646656433. The next prime is 646656487. The reversal of 646656436 is 634656646.

It is a hoax number, since the sum of its digits (46) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646656433) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1225 + ... + 35983.

Almost surely, 2^646656436 is an apocalyptic number.

It is an amenable number.

646656436 is a deficient number, since it is larger than the sum of its proper divisors (485268204).

646656436 is a wasteful number, since it uses less digits than its factorization.

646656436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39414 (or 39412 counting only the distinct ones).

The product of its digits is 1866240, while the sum is 46.

The square root of 646656436 is about 25429.4403398895. The cubic root of 646656436 is about 864.7512559517.

The spelling of 646656436 in words is "six hundred forty-six million, six hundred fifty-six thousand, four hundred thirty-six".