645325044220665 has 24 divisors (see below), whose sum is σ = 1119639986974080. Its totient is φ = 343842102458784.

The previous prime is 645325044220627. The next prime is 645325044220669. The reversal of 645325044220665 is 566022440523546.

645325044220665 is a `hidden beast` number, since 6 + 4 + 5 + 32 + 504 + 42 + 2 + 0 + 6 + 65 = 666.

It is not a de Polignac number, because 645325044220665 - 2⁷ = 645325044220537 is a prime.

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

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6901087287 + ... + 6901180796.

It is an arithmetic number, because the mean of its divisors is an integer number (46651666123920).

Almost surely, 2^{645325044220665} is an apocalyptic number.

It is an amenable number.

645325044220665 is a deficient number, since it is larger than the sum of its proper divisors (474314942753415).

645325044220665 is a wasteful number, since it uses less digits than its factorization.

645325044220665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13802269133 (or 13802269130 counting only the distinct ones).

The product of its (nonzero) digits is 41472000, while the sum is 54.

The spelling of 645325044220665 in words is "six hundred forty-five trillion, three hundred twenty-five billion, forty-four million, two hundred twenty thousand, six hundred sixty-five".