644104772 has 12 divisors (see below), whose sum is σ = 1193488380. Its totient is φ = 303108096.

The previous prime is 644104771. The next prime is 644104801. The reversal of 644104772 is 277401446.

It can be written as a sum of positive squares in 2 ways, for example, as 220403716 + 423701056 = 14846^2 + 20584^2 .

It is not an unprimeable number, because it can be changed into a prime (644104771) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4735997 + ... + 4736132.

It is an arithmetic number, because the mean of its divisors is an integer number (99457365).

Almost surely, 2^644104772 is an apocalyptic number.

It is an amenable number.

644104772 is a deficient number, since it is larger than the sum of its proper divisors (549383608).

644104772 is a wasteful number, since it uses less digits than its factorization.

644104772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9472150 (or 9472148 counting only the distinct ones).

The product of its (nonzero) digits is 37632, while the sum is 35.

The square root of 644104772 is about 25379.2192945331. The cubic root of 644104772 is about 863.6123393072.

The spelling of 644104772 in words is "six hundred forty-four million, one hundred four thousand, seven hundred seventy-two".