644533505335446 has 64 divisors (see below), whose sum is σ = 1313290604736000. Its totient is φ = 210823980595200.

The previous prime is 644533505335411. The next prime is 644533505335457.

644533505335446 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 644533505335446.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1263637815 + ... + 1264147773.

It is an arithmetic number, because the mean of its divisors is an integer number (20520165699000).

Almost surely, 2^{644533505335446} is an apocalyptic number.

644533505335446 is an abundant number, since it is smaller than the sum of its proper divisors (668757099400554).

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

644533505335446 is a wasteful number, since it uses less digits than its factorization.

644533505335446 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 518165.

The product of its (nonzero) digits is 466560000, while the sum is 60.

It can be divided in two parts, 64453350 and 5335446, that added together give a palindrome (69788796).

The spelling of 644533505335446 in words is "six hundred forty-four trillion, five hundred thirty-three billion, five hundred five million, three hundred thirty-five thousand, four hundred forty-six".