644403391334 has 8 divisors (see below), whose sum is σ = 972005115960. Its totient is φ = 320401686016.

The previous prime is 644403391283. The next prime is 644403391337. The reversal of 644403391334 is 433193304446.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644403391337) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 900004379 + ... + 900005094.

It is an arithmetic number, because the mean of its divisors is an integer number (121500639495).

Almost surely, 2^644403391334 is an apocalyptic number.

644403391334 is a deficient number, since it is larger than the sum of its proper divisors (327601724626).

644403391334 is a wasteful number, since it uses less digits than its factorization.

644403391334 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1800009654.

The product of its (nonzero) digits is 1119744, while the sum is 44.

The spelling of 644403391334 in words is "six hundred forty-four billion, four hundred three million, three hundred ninety-one thousand, three hundred thirty-four".