644447882 has 16 divisors (see below), whose sum is σ = 1060675560. Its totient is φ = 291824832.

The previous prime is 644447861. The next prime is 644447893. The reversal of 644447882 is 288744446.

It can be written as a sum of positive squares in 4 ways, for example, as 594335641 + 50112241 = 24379^2 + 7079^2 .

It is a super-2 number, since 2×644447882² = 830626145228571848, which contains 22 as substring.

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, 232457 + ... + 235212.

Almost surely, 2^644447882 is an apocalyptic number.

644447882 is a deficient number, since it is larger than the sum of its proper divisors (416227678).

644447882 is a wasteful number, since it uses less digits than its factorization.

644447882 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 467737.

The product of its digits is 1376256, while the sum is 47.

The square root of 644447882 is about 25385.9780587631. The cubic root of 644447882 is about 863.7656587895.

The spelling of 644447882 in words is "six hundred forty-four million, four hundred forty-seven thousand, eight hundred eighty-two".