646602728 has 8 divisors (see below), whose sum is σ = 1212380130. Its totient is φ = 323301360.

The previous prime is 646602721. The next prime is 646602731. The reversal of 646602728 is 827206646.

It can be written as a sum of positive squares in only one way, i.e., 513384964 + 133217764 = 22658^2 + 11542^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (646602721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40412663 + ... + 40412678.

Almost surely, 2^646602728 is an apocalyptic number.

It is an amenable number.

646602728 is a deficient number, since it is larger than the sum of its proper divisors (565777402).

646602728 is a wasteful number, since it uses less digits than its factorization.

646602728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80825347 (or 80825343 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 41.

The square root of 646602728 is about 25428.3842978668. The cubic root of 646602728 is about 864.7273146728.

The spelling of 646602728 in words is "six hundred forty-six million, six hundred two thousand, seven hundred twenty-eight".