687289 has 2 divisors, whose sum is σ = 687290. Its totient is φ = 687288.

The previous prime is 687277. The next prime is 687299. The reversal of 687289 is 982786.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 627264 + 60025 = 792^2 + 245^2 .

It is a cyclic number.

It is not a de Polignac number, because 687289 - 2⁷ = 687161 is a prime.

It is not a weakly prime, because it can be changed into another prime (687299) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343644 + 343645.

It is an arithmetic number, because the mean of its divisors is an integer number (343645).

2⁶⁸⁷²⁸⁹ is an apocalyptic number.

It is an amenable number.

687289 is a deficient number, since it is larger than the sum of its proper divisors (1).

687289 is an equidigital number, since it uses as much as digits as its factorization.

687289 is an evil number, because the sum of its binary digits is even.

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

The square root of 687289 is about 829.0289500373. The cubic root of 687289 is about 88.2496783260.

The spelling of 687289 in words is "six hundred eighty-seven thousand, two hundred eighty-nine".