287689 has 2 divisors, whose sum is σ = 287690. Its totient is φ = 287688.

The previous prime is 287681. The next prime is 287701. The reversal of 287689 is 986782.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 284089 + 3600 = 533^2 + 60^2 .

It is a cyclic number.

It is not a de Polignac number, because 287689 - 2³ = 287681 is a prime.

287689 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (287681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 143844 + 143845.

It is an arithmetic number, because the mean of its divisors is an integer number (143845).

287689 is a Friedman number, since it can be written as 88^2+9+6^7, using all its digits and the basic arithmetic operations.

2²⁸⁷⁶⁸⁹ is an apocalyptic number.

It is an amenable number.

287689 is a deficient number, since it is larger than the sum of its proper divisors (1).

287689 is an equidigital number, since it uses as much as digits as its factorization.

287689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 48384, while the sum is 40.

The square root of 287689 is about 536.3664791912. The cubic root of 287689 is about 66.0147655975.

The spelling of 287689 in words is "two hundred eighty-seven thousand, six hundred eighty-nine".