644373363 has 8 divisors (see below), whose sum is σ = 859930000. Its totient is φ = 429199488.

The previous prime is 644373307. The next prime is 644373377. The reversal of 644373363 is 363373446.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 644373363 - 2¹⁶ = 644307827 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (644273363) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 91738 + ... + 98511.

It is an arithmetic number, because the mean of its divisors is an integer number (107491250).

Almost surely, 2^644373363 is an apocalyptic number.

644373363 is a deficient number, since it is larger than the sum of its proper divisors (215556637).

644373363 is a wasteful number, since it uses less digits than its factorization.

644373363 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191381.

The product of its digits is 326592, while the sum is 39.

The square root of 644373363 is about 25384.5102966356. The cubic root of 644373363 is about 863.7323644321.

The spelling of 644373363 in words is "six hundred forty-four million, three hundred seventy-three thousand, three hundred sixty-three".