644297814 has 40 divisors (see below), whose sum is σ = 1493498160. Its totient is φ = 207358704.

The previous prime is 644297783. The next prime is 644297833. The reversal of 644297814 is 418792446.

644297814 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 644297814.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 63874 + ... + 73269.

It is an arithmetic number, because the mean of its divisors is an integer number (37337454).

Almost surely, 2^644297814 is an apocalyptic number.

644297814 is an abundant number, since it is smaller than the sum of its proper divisors (849200346).

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

644297814 is a wasteful number, since it uses less digits than its factorization.

644297814 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137186 (or 137177 counting only the distinct ones).

The product of its digits is 387072, while the sum is 45.

The square root of 644297814 is about 25383.0221604914. The cubic root of 644297814 is about 863.6986072604.

The spelling of 644297814 in words is "six hundred forty-four million, two hundred ninety-seven thousand, eight hundred fourteen".