644504405446 has 16 divisors (see below), whose sum is σ = 1070384523840. Its totient is φ = 288584061480.

The previous prime is 644504405431. The next prime is 644504405449.

644504405446 is nontrivially palindromic in base 10.

644504405446 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 644504405396 and 644504405405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644504405449) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 218622816 + ... + 218625763.

It is an arithmetic number, because the mean of its divisors is an integer number (66899032740).

Almost surely, 2^644504405446 is an apocalyptic number.

644504405446 is a deficient number, since it is larger than the sum of its proper divisors (425880118394).

644504405446 is a wasteful number, since it uses less digits than its factorization.

644504405446 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 437248659.

The product of its (nonzero) digits is 3686400, while the sum is 46.

The spelling of 644504405446 in words is "six hundred forty-four billion, five hundred four million, four hundred five thousand, four hundred forty-six".