644336633446 has 8 divisors (see below), whose sum is σ = 1054369036584. Its totient is φ = 292880287920.

The previous prime is 644336633407. The next prime is 644336633461.

644336633446 is nontrivially palindromic in base 10.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 644336633393 and 644336633402.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14644014375 + ... + 14644014418.

It is an arithmetic number, because the mean of its divisors is an integer number (131796129573).

Almost surely, 2^644336633446 is an apocalyptic number.

644336633446 is a deficient number, since it is larger than the sum of its proper divisors (410032403138).

644336633446 is a wasteful number, since it uses less digits than its factorization.

644336633446 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29288028806.

The product of its digits is 26873856, while the sum is 52.

The spelling of 644336633446 in words is "six hundred forty-four billion, three hundred thirty-six million, six hundred thirty-three thousand, four hundred forty-six".