644085590 has 16 divisors (see below), whose sum is σ = 1165242672. Its totient is φ = 256325664.

The previous prime is 644085587. The next prime is 644085593. The reversal of 644085590 is 95580446.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (644085587) and next prime (644085593).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644085593) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 161504 + ... + 165443.

It is an arithmetic number, because the mean of its divisors is an integer number (72827667).

Almost surely, 2^644085590 is an apocalyptic number.

644085590 is a deficient number, since it is larger than the sum of its proper divisors (521157082).

644085590 is a wasteful number, since it uses less digits than its factorization.

644085590 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 327151.

The product of its (nonzero) digits is 172800, while the sum is 41.

The square root of 644085590 is about 25378.8413841137. The cubic root of 644085590 is about 863.6037661800.

The spelling of 644085590 in words is "six hundred forty-four million, eighty-five thousand, five hundred ninety".