644822445 has 16 divisors (see below), whose sum is σ = 1032325632. Its totient is φ = 343702080.

The previous prime is 644822443. The next prime is 644822449. The reversal of 644822445 is 544228446.

It is not a de Polignac number, because 644822445 - 2¹ = 644822443 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644822443) 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, 15555 + ... + 39135.

It is an arithmetic number, because the mean of its divisors is an integer number (64520352).

Almost surely, 2^644822445 is an apocalyptic number.

It is an amenable number.

644822445 is a deficient number, since it is larger than the sum of its proper divisors (387503187).

644822445 is a wasteful number, since it uses less digits than its factorization.

644822445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25412.

The product of its digits is 245760, while the sum is 39.

The square root of 644822445 is about 25393.3543471515. The cubic root of 644822445 is about 863.9329709982.

The spelling of 644822445 in words is "six hundred forty-four million, eight hundred twenty-two thousand, four hundred forty-five".