644282464 has 24 divisors (see below), whose sum is σ = 1449636048. Its totient is φ = 276120960.

The previous prime is 644282461. The next prime is 644282477. The reversal of 644282464 is 464282446.

It is a happy number.

It is a super-2 number, since 2×644282464² = 830199786835822592, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644282461) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1437907 + ... + 1438354.

It is an arithmetic number, because the mean of its divisors is an integer number (60401502).

Almost surely, 2^644282464 is an apocalyptic number.

It is an amenable number.

644282464 is an abundant number, since it is smaller than the sum of its proper divisors (805353584).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644282464 is a wasteful number, since it uses less digits than its factorization.

644282464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2876278 (or 2876270 counting only the distinct ones).

The product of its digits is 294912, while the sum is 40.

The square root of 644282464 is about 25382.7197912280. The cubic root of 644282464 is about 863.6917481762.

The spelling of 644282464 in words is "six hundred forty-four million, two hundred eighty-two thousand, four hundred sixty-four".