644450064200 has 24 divisors (see below), whose sum is σ = 1498346399730. Its totient is φ = 257780025600.

The previous prime is 644450064197. The next prime is 644450064233. The reversal of 644450064200 is 2460054446.

It can be written as a sum of positive squares in 3 ways, for example, as 555176990404 + 89273073796 = 745102^2 + 298786^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1611124961 + ... + 1611125360.

Almost surely, 2^644450064200 is an apocalyptic number.

It is an amenable number.

644450064200 is an abundant number, since it is smaller than the sum of its proper divisors (853896335530).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644450064200 is a wasteful number, since it uses less digits than its factorization.

644450064200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3222250337 (or 3222250328 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 35.

The spelling of 644450064200 in words is "six hundred forty-four billion, four hundred fifty million, sixty-four thousand, two hundred".