644944795 has 16 divisors (see below), whose sum is σ = 844784640. Its totient is φ = 468776800.

The previous prime is 644944789. The next prime is 644944799. The reversal of 644944795 is 597449446.

644944795 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 644944795 - 2³ = 644944787 is a prime.

It is not an unprimeable number, because it can be changed into a prime (644944799) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 183000 + ... + 186490.

It is an arithmetic number, because the mean of its divisors is an integer number (52799040).

Almost surely, 2^644944795 is an apocalyptic number.

644944795 is a deficient number, since it is larger than the sum of its proper divisors (199839845).

644944795 is a wasteful number, since it uses less digits than its factorization.

644944795 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6866.

The product of its digits is 4354560, while the sum is 52.

The square root of 644944795 is about 25395.7633277679. The cubic root of 644944795 is about 863.9876090437.

The spelling of 644944795 in words is "six hundred forty-four million, nine hundred forty-four thousand, seven hundred ninety-five".