646687972 has 24 divisors (see below), whose sum is σ = 1305938816. Its totient is φ = 274459968.

The previous prime is 646687969. The next prime is 646687997. The reversal of 646687972 is 279786646.

646687972 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 109233 + ... + 115000.

Almost surely, 2^646687972 is an apocalyptic number.

It is an amenable number.

646687972 is an abundant number, since it is smaller than the sum of its proper divisors (659250844).

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

646687972 is a wasteful number, since it uses less digits than its factorization.

646687972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 224347 (or 224345 counting only the distinct ones).

The product of its digits is 6096384, while the sum is 55.

The square root of 646687972 is about 25430.0604010293. The cubic root of 646687972 is about 864.7653130567.

The spelling of 646687972 in words is "six hundred forty-six million, six hundred eighty-seven thousand, nine hundred seventy-two".