646481872 has 10 divisors (see below), whose sum is σ = 1252558658. Its totient is φ = 323240928.

The previous prime is 646481867. The next prime is 646481873. The reversal of 646481872 is 278184646.

It can be written as a sum of positive squares in only one way, i.e., 598095936 + 48385936 = 24456^2 + 6956^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646481873) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20202543 + ... + 20202574.

Almost surely, 2^646481872 is an apocalyptic number.

It is an amenable number.

646481872 is a deficient number, since it is larger than the sum of its proper divisors (606076786).

646481872 is a wasteful number, since it uses less digits than its factorization.

646481872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40405125 (or 40405119 counting only the distinct ones).

The product of its digits is 516096, while the sum is 46.

The square root of 646481872 is about 25426.0077873031. The cubic root of 646481872 is about 864.6734361517.

The spelling of 646481872 in words is "six hundred forty-six million, four hundred eighty-one thousand, eight hundred seventy-two".