645444599 has 12 divisors (see below), whose sum is σ = 665712600. Its totient is φ = 625623600.

The previous prime is 645444589. The next prime is 645444617. The reversal of 645444599 is 995444546.

It is a de Polignac number, because none of the positive numbers 2^k-645444599 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645444589) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 306452 + ... + 308550.

It is an arithmetic number, because the mean of its divisors is an integer number (55476050).

Almost surely, 2^645444599 is an apocalyptic number.

645444599 is a deficient number, since it is larger than the sum of its proper divisors (20268001).

645444599 is an equidigital number, since it uses as much as digits as its factorization.

645444599 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2302 (or 2231 counting only the distinct ones).

The product of its digits is 3110400, while the sum is 50.

The square root of 645444599 is about 25405.6017248165. The cubic root of 645444599 is about 864.2107356151.

The spelling of 645444599 in words is "six hundred forty-five million, four hundred forty-four thousand, five hundred ninety-nine".