646725028 has 6 divisors (see below), whose sum is σ = 1131768806. Its totient is φ = 323362512.

The previous prime is 646724993. The next prime is 646725041. The reversal of 646725028 is 820527646.

It can be written as a sum of positive squares in only one way, i.e., 447407104 + 199317924 = 21152^2 + 14118^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80840625 + ... + 80840632.

Almost surely, 2^646725028 is an apocalyptic number.

It is an amenable number.

646725028 is a deficient number, since it is larger than the sum of its proper divisors (485043778).

646725028 is a wasteful number, since it uses less digits than its factorization.

646725028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161681261 (or 161681259 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 40.

The square root of 646725028 is about 25430.7889771434. The cubic root of 646725028 is about 864.7818301061.

The spelling of 646725028 in words is "six hundred forty-six million, seven hundred twenty-five thousand, twenty-eight".