645213534545 has 4 divisors (see below), whose sum is σ = 774256241460. Its totient is φ = 516170827632.

The previous prime is 645213534529. The next prime is 645213534547. The reversal of 645213534545 is 545435312546.

645213534545 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 178668526864 + 466545007681 = 422692^2 + 683041^2 .

It is a cyclic number.

It is not a de Polignac number, because 645213534545 - 2⁴ = 645213534529 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 645213534545.

It is not an unprimeable number, because it can be changed into a prime (645213534547) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64521353450 + ... + 64521353459.

It is an arithmetic number, because the mean of its divisors is an integer number (193564060365).

Almost surely, 2^645213534545 is an apocalyptic number.

It is an amenable number.

645213534545 is a deficient number, since it is larger than the sum of its proper divisors (129042706915).

645213534545 is a wasteful number, since it uses less digits than its factorization.

645213534545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129042706914.

The product of its digits is 4320000, while the sum is 47.

The spelling of 645213534545 in words is "six hundred forty-five billion, two hundred thirteen million, five hundred thirty-four thousand, five hundred forty-five".