645835660 has 24 divisors (see below), whose sum is σ = 1357359696. Its totient is φ = 258123840.

The previous prime is 645835643. The next prime is 645835717. The reversal of 645835660 is 66538546.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13314 + ... + 38326.

It is an arithmetic number, because the mean of its divisors is an integer number (56556654).

Almost surely, 2^645835660 is an apocalyptic number.

It is an amenable number.

645835660 is an abundant number, since it is smaller than the sum of its proper divisors (711524036).

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

645835660 is a wasteful number, since it uses less digits than its factorization.

645835660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26313 (or 26311 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 43.

The square root of 645835660 is about 25413.2969132303. The cubic root of 645835660 is about 864.3852359435.

The spelling of 645835660 in words is "six hundred forty-five million, eight hundred thirty-five thousand, six hundred sixty".