645220443884 has 12 divisors (see below), whose sum is σ = 1130528058408. Its totient is φ = 322212427200.

The previous prime is 645220443859. The next prime is 645220443911. The reversal of 645220443884 is 488344022546.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 99445037 + ... + 99451524.

It is an arithmetic number, because the mean of its divisors is an integer number (94210671534).

Almost surely, 2^645220443884 is an apocalyptic number.

It is an amenable number.

645220443884 is a deficient number, since it is larger than the sum of its proper divisors (485307614524).

645220443884 is a wasteful number, since it uses less digits than its factorization.

645220443884 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198897376 (or 198897374 counting only the distinct ones).

The product of its (nonzero) digits is 5898240, while the sum is 50.

The spelling of 645220443884 in words is "six hundred forty-five billion, two hundred twenty million, four hundred forty-three thousand, eight hundred eighty-four".