644195591446 has 16 divisors (see below), whose sum is σ = 1063466901648. Its totient is φ = 290224883200.

The previous prime is 644195591443. The next prime is 644195591461.

644195591446 is nontrivially palindromic in base 10.

644195591446 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644195591441) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 129562195 + ... + 129567166.

It is an arithmetic number, because the mean of its divisors is an integer number (66466681353).

Almost surely, 2^644195591446 is an apocalyptic number.

644195591446 is a deficient number, since it is larger than the sum of its proper divisors (419271310202).

644195591446 is a wasteful number, since it uses less digits than its factorization.

644195591446 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 259129487.

The product of its digits is 18662400, while the sum is 58.

The spelling of 644195591446 in words is "six hundred forty-four billion, one hundred ninety-five million, five hundred ninety-one thousand, four hundred forty-six".