645693389 has 16 divisors (see below), whose sum is σ = 733171200. Its totient is φ = 568022400.

The previous prime is 645693361. The next prime is 645693403. The reversal of 645693389 is 983396546.

It is not a de Polignac number, because 645693389 - 2²⁰ = 644644813 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 645693389.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645693689) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33437 + ... + 49085.

It is an arithmetic number, because the mean of its divisors is an integer number (45823200).

Almost surely, 2^645693389 is an apocalyptic number.

It is an amenable number.

645693389 is a deficient number, since it is larger than the sum of its proper divisors (87477811).

645693389 is a wasteful number, since it uses less digits than its factorization.

645693389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15713 (or 15691 counting only the distinct ones).

The product of its digits is 4199040, while the sum is 53.

The square root of 645693389 is about 25410.4976141751. The cubic root of 645693389 is about 864.3217595357.

The spelling of 645693389 in words is "six hundred forty-five million, six hundred ninety-three thousand, three hundred eighty-nine".