644343448 has 32 divisors (see below), whose sum is σ = 1389024000. Its totient is φ = 274489632.

The previous prime is 644343439. The next prime is 644343449. The reversal of 644343448 is 844343446.

It is a self number, because there is not a number n which added to its sum of digits gives 644343448.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644343449) 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, 25098 + ... + 43801.

It is an arithmetic number, because the mean of its divisors is an integer number (43407000).

Almost surely, 2^644343448 is an apocalyptic number.

It is an amenable number.

644343448 is an abundant number, since it is smaller than the sum of its proper divisors (744680552).

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

644343448 is a wasteful number, since it uses less digits than its factorization.

644343448 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69079 (or 69075 counting only the distinct ones).

The product of its digits is 442368, while the sum is 40.

The square root of 644343448 is about 25383.9210525088. The cubic root of 644343448 is about 863.7189979818.

The spelling of 644343448 in words is "six hundred forty-four million, three hundred forty-three thousand, four hundred forty-eight".