644828848 has 10 divisors (see below), whose sum is σ = 1249355924. Its totient is φ = 322414416.

The previous prime is 644828831. The next prime is 644828879. The reversal of 644828848 is 848828446.

It is a junction number, because it is equal to n+sod(n) for n = 644828795 and 644828804.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20150886 + ... + 20150917.

Almost surely, 2^644828848 is an apocalyptic number.

It is an amenable number.

644828848 is a deficient number, since it is larger than the sum of its proper divisors (604527076).

644828848 is a wasteful number, since it uses less digits than its factorization.

644828848 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40301811 (or 40301805 counting only the distinct ones).

The product of its digits is 3145728, while the sum is 52.

The square root of 644828848 is about 25393.4804231322. The cubic root of 644828848 is about 863.9358305680.

The spelling of 644828848 in words is "six hundred forty-four million, eight hundred twenty-eight thousand, eight hundred forty-eight".