645593836 has 24 divisors (see below), whose sum is σ = 1197319536. Its totient is φ = 303536640.

The previous prime is 645593801. The next prime is 645593849. The reversal of 645593836 is 638395546.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 645593836.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 86235 + ... + 93421.

It is an arithmetic number, because the mean of its divisors is an integer number (49888314).

Almost surely, 2^645593836 is an apocalyptic number.

It is an amenable number.

645593836 is a deficient number, since it is larger than the sum of its proper divisors (551725700).

645593836 is a wasteful number, since it uses less digits than its factorization.

645593836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8529 (or 8527 counting only the distinct ones).

The product of its digits is 2332800, while the sum is 49.

The square root of 645593836 is about 25408.5386435348. The cubic root of 645593836 is about 864.2773368793.

The spelling of 645593836 in words is "six hundred forty-five million, five hundred ninety-three thousand, eight hundred thirty-six".