644046746 has 32 divisors (see below), whose sum is σ = 1125949440. Its totient is φ = 270593136.

The previous prime is 644046721. The next prime is 644046749. The reversal of 644046746 is 647640446.

It is a super-2 number, since 2×644046746² = 829592422066377032, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (644046749) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 207635 + ... + 210713.

It is an arithmetic number, because the mean of its divisors is an integer number (35185920).

Almost surely, 2^644046746 is an apocalyptic number.

644046746 is a deficient number, since it is larger than the sum of its proper divisors (481902694).

644046746 is a wasteful number, since it uses less digits than its factorization.

644046746 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3378.

The product of its (nonzero) digits is 387072, while the sum is 41.

The square root of 644046746 is about 25378.0760894123. The cubic root of 644046746 is about 863.5864048751.

The spelling of 644046746 in words is "six hundred forty-four million, forty-six thousand, seven hundred forty-six".