645867259 has 2 divisors, whose sum is σ = 645867260. Its totient is φ = 645867258.

The previous prime is 645867161. The next prime is 645867269. The reversal of 645867259 is 952768546.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 645867259 - 2²¹ = 643770107 is a prime.

It is not a weakly prime, because it can be changed into another prime (645867269) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322933629 + 322933630.

It is an arithmetic number, because the mean of its divisors is an integer number (322933630).

Almost surely, 2^645867259 is an apocalyptic number.

645867259 is a deficient number, since it is larger than the sum of its proper divisors (1).

645867259 is an equidigital number, since it uses as much as digits as its factorization.

645867259 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3628800, while the sum is 52.

The square root of 645867259 is about 25413.9186077236. The cubic root of 645867259 is about 864.3993330610.

The spelling of 645867259 in words is "six hundred forty-five million, eight hundred sixty-seven thousand, two hundred fifty-nine".