645643626346545 has 32 divisors (see below), whose sum is σ = 1045127419392000. Its totient is φ = 340332946156224.

The previous prime is 645643626346507. The next prime is 645643626346687. The reversal of 645643626346545 is 545643626346546.

It is not a de Polignac number, because 645643626346545 - 2²⁰ = 645643625297969 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 645643626346545.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 693842695 + ... + 694772604.

It is an arithmetic number, because the mean of its divisors is an integer number (32660231856000).

Almost surely, 2^{645643626346545} is an apocalyptic number.

It is an amenable number.

645643626346545 is a deficient number, since it is larger than the sum of its proper divisors (399483793045455).

645643626346545 is a wasteful number, since it uses less digits than its factorization.

645643626346545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1388615669.

The product of its digits is 4478976000, while the sum is 69.

Subtracting from 645643626346545 its reverse (545643626346546), we obtain a palindrome (99999999999999).

The spelling of 645643626346545 in words is "six hundred forty-five trillion, six hundred forty-three billion, six hundred twenty-six million, three hundred forty-six thousand, five hundred forty-five".