644624426446 has 128 divisors (see below), whose sum is σ = 1311927321600. Its totient is φ = 229400156160.

The previous prime is 644624426437. The next prime is 644624426473.

644624426446 is nontrivially palindromic in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 644624426393 and 644624426402.

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 63 ways as a sum of consecutive naturals, for example, 160392225 + ... + 160396243.

It is an arithmetic number, because the mean of its divisors is an integer number (10249432200).

Almost surely, 2^644624426446 is an apocalyptic number.

644624426446 is an abundant number, since it is smaller than the sum of its proper divisors (667302895154).

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

644624426446 is a wasteful number, since it uses less digits than its factorization.

644624426446 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4874.

The product of its digits is 21233664, while the sum is 52.

The spelling of 644624426446 in words is "six hundred forty-four billion, six hundred twenty-four million, four hundred twenty-six thousand, four hundred forty-six".