644465398 has 8 divisors (see below), whose sum is σ = 967148280. Its totient is φ = 322082640.

The previous prime is 644465383. The next prime is 644465401. The reversal of 644465398 is 893564446.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 69583 + ... + 78298.

It is an arithmetic number, because the mean of its divisors is an integer number (120893535).

Almost surely, 2^644465398 is an apocalyptic number.

644465398 is a deficient number, since it is larger than the sum of its proper divisors (322682882).

644465398 is a wasteful number, since it uses less digits than its factorization.

644465398 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150062.

The product of its digits is 2488320, while the sum is 49.

The square root of 644465398 is about 25386.3230500205. The cubic root of 644465398 is about 863.7734843937.

The spelling of 644465398 in words is "six hundred forty-four million, four hundred sixty-five thousand, three hundred ninety-eight".