644933222 has 4 divisors (see below), whose sum is σ = 967399836. Its totient is φ = 322466610.

The previous prime is 644933213. The next prime is 644933279. The reversal of 644933222 is 222339446.

644933222 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161233304 + ... + 161233307.

It is an arithmetic number, because the mean of its divisors is an integer number (241849959).

Almost surely, 2^644933222 is an apocalyptic number.

644933222 is a deficient number, since it is larger than the sum of its proper divisors (322466614).

644933222 is a wasteful number, since it uses less digits than its factorization.

644933222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 322466613.

The product of its digits is 62208, while the sum is 35.

The square root of 644933222 is about 25395.5354737796. The cubic root of 644933222 is about 863.9824411655.

The spelling of 644933222 in words is "six hundred forty-four million, nine hundred thirty-three thousand, two hundred twenty-two".