645889929988545 has 80 divisors (see below), whose sum is σ = 1297210766626368. Its totient is φ = 304695003749760.

The previous prime is 645889929988507. The next prime is 645889929988561. The reversal of 645889929988545 is 545889929988546.

645889929988545 is a `hidden beast` number, since 6 + 4 + 588 + 9 + 9 + 2 + 9 + 9 + 8 + 8 + 5 + 4 + 5 = 666.

It is not a de Polignac number, because 645889929988545 - 2²⁵ = 645889896434113 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (99).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 1959036579 + ... + 1959366248.

Almost surely, 2^{645889929988545} is an apocalyptic number.

It is an amenable number.

645889929988545 is an abundant number, since it is smaller than the sum of its proper divisors (651320836637823).

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

645889929988545 is a wasteful number, since it uses less digits than its factorization.

645889929988545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3918402892 (or 3918402883 counting only the distinct ones).

The product of its digits is 644972544000, while the sum is 99.

Subtracting from 645889929988545 its reverse (545889929988546), we obtain a palindrome (99999999999999).

The spelling of 645889929988545 in words is "six hundred forty-five trillion, eight hundred eighty-nine billion, nine hundred twenty-nine million, nine hundred eighty-eight thousand, five hundred forty-five".