644004046 has 32 divisors (see below), whose sum is σ = 1123246080. Its totient is φ = 271234656.

The previous prime is 644004043. The next prime is 644004061. The reversal of 644004046 is 640400446.

644004046 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×644004046² = 829482422528740232, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644004041) 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, 192141 + ... + 195463.

It is an arithmetic number, because the mean of its divisors is an integer number (35101440).

Almost surely, 2^644004046 is an apocalyptic number.

644004046 is a deficient number, since it is larger than the sum of its proper divisors (479242034).

644004046 is a wasteful number, since it uses less digits than its factorization.

644004046 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3568.

The product of its (nonzero) digits is 9216, while the sum is 28.

The square root of 644004046 is about 25377.2347981414. The cubic root of 644004046 is about 863.5673193275.

The spelling of 644004046 in words is "six hundred forty-four million, four thousand, forty-six".