644444444444 has 24 divisors (see below), whose sum is σ = 1195434318960. Its totient is φ = 302933581056.

The previous prime is 644444444443. The next prime is 644444444459. The reversal of 644444444444 is 444444444446.

644444444444 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

644444444444 is a modest number, since divided by 4444444 gives 64444 as remainder.

It is a nialpdrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 644444444392 and 644444444401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644444444443) 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, 5162759 + ... + 5286110.

It is an arithmetic number, because the mean of its divisors is an integer number (49809763290).

Almost surely, 2^644444444444 is an apocalyptic number.

It is an amenable number.

644444444444 is a deficient number, since it is larger than the sum of its proper divisors (550989874516).

644444444444 is a wasteful number, since it uses less digits than its factorization.

644444444444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10449797 (or 10449795 counting only the distinct ones).

The product of its digits is 25165824, while the sum is 50.

The spelling of 644444444444 in words is "six hundred forty-four billion, four hundred forty-four million, four hundred forty-four thousand, four hundred forty-four".