645694725883 has 4 divisors (see below), whose sum is σ = 683676768600. Its totient is φ = 607712683168.

The previous prime is 645694725877. The next prime is 645694725887. The reversal of 645694725883 is 388527496546.

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

It is a cyclic number.

It is not a de Polignac number, because 645694725883 - 2²¹ = 645692628731 is a prime.

It is a Smith number, since the sum of its digits (67) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645694725887) 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, 18991021333 + ... + 18991021366.

It is an arithmetic number, because the mean of its divisors is an integer number (170919192150).

Almost surely, 2^645694725883 is an apocalyptic number.

645694725883 is a deficient number, since it is larger than the sum of its proper divisors (37982042717).

645694725883 is a wasteful number, since it uses less digits than its factorization.

645694725883 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37982042716.

The product of its digits is 348364800, while the sum is 67.

The spelling of 645694725883 in words is "six hundred forty-five billion, six hundred ninety-four million, seven hundred twenty-five thousand, eight hundred eighty-three".