645325044220664 has 32 divisors (see below), whose sum is σ = 1251560036067840. Its totient is φ = 311618098293600.

The previous prime is 645325044220627. The next prime is 645325044220669. The reversal of 645325044220664 is 466022440523546.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645325044220669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2649691994 + ... + 2649935529.

It is an arithmetic number, because the mean of its divisors is an integer number (39111251127120).

Almost surely, 2^{645325044220664} is an apocalyptic number.

It is an amenable number.

645325044220664 is a deficient number, since it is larger than the sum of its proper divisors (606234991847176).

645325044220664 is a wasteful number, since it uses less digits than its factorization.

645325044220664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5299628051 (or 5299628047 counting only the distinct ones).

The product of its (nonzero) digits is 33177600, while the sum is 53.

The spelling of 645325044220664 in words is "six hundred forty-five trillion, three hundred twenty-five billion, forty-four million, two hundred twenty thousand, six hundred sixty-four".