644041281394 has 32 divisors (see below), whose sum is σ = 1110054839040. Its totient is φ = 274522355712.

The previous prime is 644041281391. The next prime is 644041281409. The reversal of 644041281394 is 493182140446.

It is not an unprimeable number, because it can be changed into a prime (644041281391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12357262 + ... + 12409270.

It is an arithmetic number, because the mean of its divisors is an integer number (34689213720).

Almost surely, 2^644041281394 is an apocalyptic number.

644041281394 is a deficient number, since it is larger than the sum of its proper divisors (466013557646).

644041281394 is a wasteful number, since it uses less digits than its factorization.

644041281394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56794.

The product of its (nonzero) digits is 663552, while the sum is 46.

The spelling of 644041281394 in words is "six hundred forty-four billion, forty-one million, two hundred eighty-one thousand, three hundred ninety-four".