640589 has 2 divisors, whose sum is σ = 640590. Its totient is φ = 640588.

The previous prime is 640583. The next prime is 640613. The reversal of 640589 is 985046.

640589 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 422500 + 218089 = 650^2 + 467^2 .

It is a cyclic number.

It is not a de Polignac number, because 640589 - 2⁸ = 640333 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640583) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320294 + 320295.

It is an arithmetic number, because the mean of its divisors is an integer number (320295).

2⁶⁴⁰⁵⁸⁹ is an apocalyptic number.

It is an amenable number.

640589 is a deficient number, since it is larger than the sum of its proper divisors (1).

640589 is an equidigital number, since it uses as much as digits as its factorization.

640589 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 640589 is about 800.3680403414. The cubic root of 640589 is about 86.2038162044.

The spelling of 640589 in words is "six hundred forty thousand, five hundred eighty-nine".