645593243 has 2 divisors, whose sum is σ = 645593244. Its totient is φ = 645593242.

The previous prime is 645593227. The next prime is 645593261. The reversal of 645593243 is 342395546.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 645593243 - 2⁴ = 645593227 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 645593243.

It is not a weakly prime, because it can be changed into another prime (645593743) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322796621 + 322796622.

It is an arithmetic number, because the mean of its divisors is an integer number (322796622).

Almost surely, 2^645593243 is an apocalyptic number.

645593243 is a deficient number, since it is larger than the sum of its proper divisors (1).

645593243 is an equidigital number, since it uses as much as digits as its factorization.

645593243 is an evil number, because the sum of its binary digits is even.

The product of its digits is 388800, while the sum is 41.

The square root of 645593243 is about 25408.5269742266. The cubic root of 645593243 is about 864.2770722564.

The spelling of 645593243 in words is "six hundred forty-five million, five hundred ninety-three thousand, two hundred forty-three".