644485288 has 16 divisors (see below), whose sum is σ = 1247391360. Its totient is φ = 311847600.

The previous prime is 644485279. The next prime is 644485297. The reversal of 644485288 is 882584446.

It is an interprime number because it is at equal distance from previous prime (644485279) and next prime (644485297).

It is a super-2 number, since 2×644485288² = 830722572896885888, which contains 22 as substring.

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 in 3 ways as a sum of consecutive naturals, for example, 1299118 + ... + 1299613.

It is an arithmetic number, because the mean of its divisors is an integer number (77961960).

Almost surely, 2^644485288 is an apocalyptic number.

It is an amenable number.

644485288 is a deficient number, since it is larger than the sum of its proper divisors (602906072).

644485288 is a wasteful number, since it uses less digits than its factorization.

644485288 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2598768 (or 2598764 counting only the distinct ones).

The product of its digits is 1966080, while the sum is 49.

The square root of 644485288 is about 25386.7147933717. The cubic root of 644485288 is about 863.7823704554.

The spelling of 644485288 in words is "six hundred forty-four million, four hundred eighty-five thousand, two hundred eighty-eight".