644352236 has 24 divisors (see below), whose sum is σ = 1269811200. Its totient is φ = 283438800.

The previous prime is 644352223. The next prime is 644352251. The reversal of 644352236 is 632253446.

It is a junction number, because it is equal to n+sod(n) for n = 644352196 and 644352205.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 234836 + ... + 237563.

It is an arithmetic number, because the mean of its divisors is an integer number (52908800).

Almost surely, 2^644352236 is an apocalyptic number.

It is an amenable number.

644352236 is a deficient number, since it is larger than the sum of its proper divisors (625458964).

644352236 is a wasteful number, since it uses less digits than its factorization.

644352236 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 472445 (or 472443 counting only the distinct ones).

The product of its digits is 103680, while the sum is 35.

The square root of 644352236 is about 25384.0941536231. The cubic root of 644352236 is about 863.7229246290.

The spelling of 644352236 in words is "six hundred forty-four million, three hundred fifty-two thousand, two hundred thirty-six".