644117272 has 16 divisors (see below), whose sum is σ = 1212213600. Its totient is φ = 320860320.

The previous prime is 644117269. The next prime is 644117273. The reversal of 644117272 is 272711446.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644117273) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 147504 + ... + 151807.

It is an arithmetic number, because the mean of its divisors is an integer number (75763350).

Almost surely, 2^644117272 is an apocalyptic number.

It is an amenable number.

644117272 is a deficient number, since it is larger than the sum of its proper divisors (568096328).

644117272 is a wasteful number, since it uses less digits than its factorization.

644117272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 299586 (or 299582 counting only the distinct ones).

The product of its digits is 18816, while the sum is 34.

The square root of 644117272 is about 25379.4655578087. The cubic root of 644117272 is about 863.6179259161.

The spelling of 644117272 in words is "six hundred forty-four million, one hundred seventeen thousand, two hundred seventy-two".