644884048 has 10 divisors (see below), whose sum is σ = 1249462874. Its totient is φ = 322442016.

The previous prime is 644884013. The next prime is 644884061. The reversal of 644884048 is 840488446.

It can be written as a sum of positive squares in only one way, i.e., 638673984 + 6210064 = 25272^2 + 2492^2 .

It is a junction number, because it is equal to n+sod(n) for n = 644883989 and 644884007.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20152611 + ... + 20152642.

Almost surely, 2^644884048 is an apocalyptic number.

It is an amenable number.

644884048 is a deficient number, since it is larger than the sum of its proper divisors (604578826).

644884048 is a wasteful number, since it uses less digits than its factorization.

644884048 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40305261 (or 40305255 counting only the distinct ones).

The product of its (nonzero) digits is 786432, while the sum is 46.

The square root of 644884048 is about 25394.5672930255. The cubic root of 644884048 is about 863.9604820174.

The spelling of 644884048 in words is "six hundred forty-four million, eight hundred eighty-four thousand, forty-eight".