645245500665 has 16 divisors (see below), whose sum is σ = 1032508354176. Its totient is φ = 344092416000.

The previous prime is 645245500657. The next prime is 645245500667. The reversal of 645245500665 is 566005542546.

It is not a de Polignac number, because 645245500665 - 2³ = 645245500657 is a prime.

It is a super-2 number, since 2×645245500665² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (645245500667) 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 15 ways as a sum of consecutive naturals, for example, 2268616 + ... + 2537145.

It is an arithmetic number, because the mean of its divisors is an integer number (64531772136).

Almost surely, 2^645245500665 is an apocalyptic number.

It is an amenable number.

645245500665 is a deficient number, since it is larger than the sum of its proper divisors (387262853511).

645245500665 is a wasteful number, since it uses less digits than its factorization.

645245500665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4814720.

The product of its (nonzero) digits is 4320000, while the sum is 48.

The spelling of 645245500665 in words is "six hundred forty-five billion, two hundred forty-five million, five hundred thousand, six hundred sixty-five".