644242424044 has 12 divisors (see below), whose sum is σ = 1132141500000. Its totient is φ = 320773424048.

The previous prime is 644242424011. The next prime is 644242424053. The reversal of 644242424044 is 440424242446.

It is a junction number, because it is equal to n+sod(n) for n = 644242423988 and 644242424006.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 336945919 + ... + 336947830.

It is an arithmetic number, because the mean of its divisors is an integer number (94345125000).

Almost surely, 2^644242424044 is an apocalyptic number.

It is an amenable number.

644242424044 is a deficient number, since it is larger than the sum of its proper divisors (487899075956).

644242424044 is a wasteful number, since it uses less digits than its factorization.

644242424044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 673893992 (or 673893990 counting only the distinct ones).

The product of its (nonzero) digits is 786432, while the sum is 40.

The spelling of 644242424044 in words is "six hundred forty-four billion, two hundred forty-two million, four hundred twenty-four thousand, forty-four".