644443344446 has 32 divisors (see below), whose sum is σ = 1085941219968. Its totient is φ = 284294031840.

The previous prime is 644443344379. The next prime is 644443344539.

644443344446 is nontrivially palindromic in base 10.

It is a Smith number, since the sum of its digits (50) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 644443344394 and 644443344403.

It is a congruent number.

It is an unprimeable number.

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, 2021000 + ... + 2318043.

It is an arithmetic number, because the mean of its divisors is an integer number (33935663124).

Almost surely, 2^644443344446 is an apocalyptic number.

644443344446 is a deficient number, since it is larger than the sum of its proper divisors (441497875522).

644443344446 is a wasteful number, since it uses less digits than its factorization.

644443344446 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4339256.

The product of its digits is 21233664, while the sum is 50.

It can be divided in two parts, 644443 and 344446, that added together give a palindrome (988889).

The spelling of 644443344446 in words is "six hundred forty-four billion, four hundred forty-three million, three hundred forty-four thousand, four hundred forty-six".