645999365 has 16 divisors (see below), whose sum is σ = 850409280. Its totient is φ = 467185920.

The previous prime is 645999329. The next prime is 645999397. The reversal of 645999365 is 563999546.

It is not a de Polignac number, because 645999365 - 2¹⁰ = 645998341 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 645999365.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22964 + ... + 42653.

It is an arithmetic number, because the mean of its divisors is an integer number (53150580).

Almost surely, 2^645999365 is an apocalyptic number.

It is an amenable number.

645999365 is a deficient number, since it is larger than the sum of its proper divisors (204409915).

645999365 is a wasteful number, since it uses less digits than its factorization.

645999365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65812.

The product of its digits is 7873200, while the sum is 56.

The square root of 645999365 is about 25416.5175624042. The cubic root of 645999365 is about 864.4582639285.

The spelling of 645999365 in words is "six hundred forty-five million, nine hundred ninety-nine thousand, three hundred sixty-five".