644053223 has 16 divisors (see below), whose sum is σ = 713494656. Its totient is φ = 576495840.

The previous prime is 644053219. The next prime is 644053229. The reversal of 644053223 is 322350446.

It is a cyclic number.

It is not a de Polignac number, because 644053223 - 2² = 644053219 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644053229) 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, 202040 + ... + 205202.

It is an arithmetic number, because the mean of its divisors is an integer number (44593416).

Almost surely, 2^644053223 is an apocalyptic number.

644053223 is a deficient number, since it is larger than the sum of its proper divisors (69441433).

644053223 is a wasteful number, since it uses less digits than its factorization.

644053223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3454.

The product of its (nonzero) digits is 17280, while the sum is 29.

The square root of 644053223 is about 25378.2036992377. The cubic root of 644053223 is about 863.5892998152.

The spelling of 644053223 in words is "six hundred forty-four million, fifty-three thousand, two hundred twenty-three".