644067022 has 12 divisors (see below), whose sum is σ = 1009932840. Its totient is φ = 308031548.

The previous prime is 644067019. The next prime is 644067037. The reversal of 644067022 is 220760446.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 303322 + ... + 305437.

It is an arithmetic number, because the mean of its divisors is an integer number (84161070).

Almost surely, 2^644067022 is an apocalyptic number.

644067022 is a deficient number, since it is larger than the sum of its proper divisors (365865818).

644067022 is a wasteful number, since it uses less digits than its factorization.

644067022 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 608807 (or 608784 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 31.

The square root of 644067022 is about 25378.4755649349. The cubic root of 644067022 is about 863.5954673095.

The spelling of 644067022 in words is "six hundred forty-four million, sixty-seven thousand, twenty-two".