644381393882 has 8 divisors (see below), whose sum is σ = 966684157056. Its totient is φ = 322153341532.

The previous prime is 644381393869. The next prime is 644381393891. The reversal of 644381393882 is 288393183446.

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

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 3 ways as a sum of consecutive naturals, for example, 18656138 + ... + 18690645.

It is an arithmetic number, because the mean of its divisors is an integer number (120835519632).

Almost surely, 2^644381393882 is an apocalyptic number.

644381393882 is a deficient number, since it is larger than the sum of its proper divisors (322302763174).

644381393882 is a wasteful number, since it uses less digits than its factorization.

644381393882 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37355412.

The product of its digits is 23887872, while the sum is 59.

The spelling of 644381393882 in words is "six hundred forty-four billion, three hundred eighty-one million, three hundred ninety-three thousand, eight hundred eighty-two".