644453323354446 has 64 divisors (see below), whose sum is σ = 1336757790491136. Its totient is φ = 206957255644800.

The previous prime is 644453323354439. The next prime is 644453323354447.

644453323354446 is nontrivially palindromic in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 644453323354446.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644453323354447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 185113456 + ... + 188562716.

It is an arithmetic number, because the mean of its divisors is an integer number (20886840476424).

Almost surely, 2^{644453323354446} is an apocalyptic number.

644453323354446 is an abundant number, since it is smaller than the sum of its proper divisors (692304467136690).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644453323354446 is a wasteful number, since it uses less digits than its factorization.

644453323354446 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3457577.

The product of its digits is 597196800, while the sum is 60.

The spelling of 644453323354446 in words is "six hundred forty-four trillion, four hundred fifty-three billion, three hundred twenty-three million, three hundred fifty-four thousand, four hundred forty-six".