643589 has 2 divisors, whose sum is σ = 643590. Its totient is φ = 643588.

The previous prime is 643583. The next prime is 643619. The reversal of 643589 is 985346.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 550564 + 93025 = 742^2 + 305^2 .

It is a cyclic number.

It is not a de Polignac number, because 643589 - 2¹² = 639493 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 643589.

It is not a weakly prime, because it can be changed into another prime (643583) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321794 + 321795.

It is an arithmetic number, because the mean of its divisors is an integer number (321795).

2⁶⁴³⁵⁸⁹ is an apocalyptic number.

It is an amenable number.

643589 is a deficient number, since it is larger than the sum of its proper divisors (1).

643589 is an equidigital number, since it uses as much as digits as its factorization.

643589 is an evil number, because the sum of its binary digits is even.

The product of its digits is 25920, while the sum is 35.

The square root of 643589 is about 802.2399890307. The cubic root of 643589 is about 86.3381762943.

The spelling of 643589 in words is "six hundred forty-three thousand, five hundred eighty-nine".