644513199 has 16 divisors (see below), whose sum is σ = 978234624. Its totient is φ = 373630400.

The previous prime is 644513171. The next prime is 644513201. The reversal of 644513199 is 991315446.

It is not a de Polignac number, because 644513199 - 2⁵ = 644513167 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 644513199.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644513119) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 423822 + ... + 425339.

It is an arithmetic number, because the mean of its divisors is an integer number (61139664).

Almost surely, 2^644513199 is an apocalyptic number.

644513199 is a gapful number since it is divisible by the number (69) formed by its first and last digit.

644513199 is a deficient number, since it is larger than the sum of its proper divisors (333721425).

644513199 is a wasteful number, since it uses less digits than its factorization.

644513199 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 849198.

The product of its digits is 116640, while the sum is 42.

The square root of 644513199 is about 25387.2645040776. The cubic root of 644513199 is about 863.7948396729.

The spelling of 644513199 in words is "six hundred forty-four million, five hundred thirteen thousand, one hundred ninety-nine".