644252958 has 24 divisors (see below), whose sum is σ = 1396661448. Its totient is φ = 214630992.

The previous prime is 644252957. The next prime is 644253011. The reversal of 644252958 is 859252446.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644252957) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 26760 + ... + 44772.

It is an arithmetic number, because the mean of its divisors is an integer number (58194227).

Almost surely, 2^644252958 is an apocalyptic number.

644252958 is an abundant number, since it is smaller than the sum of its proper divisors (752408490).

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

644252958 is a wasteful number, since it uses less digits than its factorization.

644252958 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20008 (or 20005 counting only the distinct ones).

The product of its digits is 691200, while the sum is 45.

The square root of 644252958 is about 25382.1385623828. The cubic root of 644252958 is about 863.6785632357.

The spelling of 644252958 in words is "six hundred forty-four million, two hundred fifty-two thousand, nine hundred fifty-eight".