8661689 has 2 divisors, whose sum is σ = 8661690. Its totient is φ = 8661688.

The previous prime is 8661683. The next prime is 8661703. The reversal of 8661689 is 9861668.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6165289 + 2496400 = 2483^2 + 1580^2 .

It is a cyclic number.

It is not a de Polignac number, because 8661689 - 2⁴ = 8661673 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (8661683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4330844 + 4330845.

It is an arithmetic number, because the mean of its divisors is an integer number (4330845).

Almost surely, 2^8661689 is an apocalyptic number.

It is an amenable number.

8661689 is a deficient number, since it is larger than the sum of its proper divisors (1).

8661689 is an equidigital number, since it uses as much as digits as its factorization.

8661689 is an evil number, because the sum of its binary digits is even.

The product of its digits is 124416, while the sum is 44.

The square root of 8661689 is about 2943.0747527034. The cubic root of 8661689 is about 205.3686722946.

The spelling of 8661689 in words is "eight million, six hundred sixty-one thousand, six hundred eighty-nine".