644330033399 has 32 divisors (see below), whose sum is σ = 752170668480. Its totient is φ = 546761290752.

The previous prime is 644330033393. The next prime is 644330033453. The reversal of 644330033399 is 993330033446.

It is a cyclic number.

It is not a de Polignac number, because 644330033399 - 2²⁴ = 644313256183 is a prime.

It is a super-2 number, since 2×644330033399² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644330033393) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3314339 + ... + 3503355.

It is an arithmetic number, because the mean of its divisors is an integer number (23505333390).

Almost surely, 2^644330033399 is an apocalyptic number.

644330033399 is a deficient number, since it is larger than the sum of its proper divisors (107840635081).

644330033399 is a wasteful number, since it uses less digits than its factorization.

644330033399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 189459.

The product of its (nonzero) digits is 1889568, while the sum is 47.

Adding to 644330033399 its sum of digits (47), we get a palindrome (644330033446).

The spelling of 644330033399 in words is "six hundred forty-four billion, three hundred thirty million, thirty-three thousand, three hundred ninety-nine".