644148344 has 16 divisors (see below), whose sum is σ = 1380318000. Its totient is φ = 276063552.

The previous prime is 644148341. The next prime is 644148391. The reversal of 644148344 is 443841446.

It is a happy number.

644148344 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 644148298 and 644148307.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644148341) 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, 5751269 + ... + 5751380.

It is an arithmetic number, because the mean of its divisors is an integer number (86269875).

Almost surely, 2^644148344 is an apocalyptic number.

It is an amenable number.

644148344 is an abundant number, since it is smaller than the sum of its proper divisors (736169656).

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

644148344 is a wasteful number, since it uses less digits than its factorization.

644148344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11502662 (or 11502658 counting only the distinct ones).

The product of its digits is 147456, while the sum is 38.

The square root of 644148344 is about 25380.0776988566. The cubic root of 644148344 is about 863.6318125720.

The spelling of 644148344 in words is "six hundred forty-four million, one hundred forty-eight thousand, three hundred forty-four".