644448490 has 48 divisors (see below), whose sum is σ = 1378156032. Its totient is φ = 216244896.

The previous prime is 644448487. The next prime is 644448547. The reversal of 644448490 is 94844446.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9039 + ... + 37021.

It is an arithmetic number, because the mean of its divisors is an integer number (28711584).

Almost surely, 2^644448490 is an apocalyptic number.

644448490 is an abundant number, since it is smaller than the sum of its proper divisors (733707542).

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

644448490 is a wasteful number, since it uses less digits than its factorization.

644448490 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28051 (or 28044 counting only the distinct ones).

The product of its (nonzero) digits is 442368, while the sum is 43.

The square root of 644448490 is about 25385.9900338750. The cubic root of 644448490 is about 863.7659304273.

The spelling of 644448490 in words is "six hundred forty-four million, four hundred forty-eight thousand, four hundred ninety".