646464644 has 36 divisors (see below), whose sum is σ = 1393437276. Its totient is φ = 260757504.

The previous prime is 646464617. The next prime is 646464653. The reversal of 646464644 is 446464646.

It can be written as a sum of positive squares in 2 ways, for example, as 579846400 + 66618244 = 24080^2 + 8162^2 .

It is a junction number, because it is equal to n+sod(n) for n = 646464595 and 646464604.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 93677 + ... + 100340.

It is an arithmetic number, because the mean of its divisors is an integer number (38706591).

Almost surely, 2^646464644 is an apocalyptic number.

It is an amenable number.

646464644 is an abundant number, since it is smaller than the sum of its proper divisors (746972632).

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

646464644 is a wasteful number, since it uses less digits than its factorization.

646464644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 194052 (or 194043 counting only the distinct ones).

The product of its digits is 1327104, while the sum is 44.

The square root of 646464644 is about 25425.6689980814. The cubic root of 646464644 is about 864.6657552319.

The spelling of 646464644 in words is "six hundred forty-six million, four hundred sixty-four thousand, six hundred forty-four".