1689659 has 2 divisors, whose sum is σ = 1689660. Its totient is φ = 1689658.

The previous prime is 1689641. The next prime is 1689661. The reversal of 1689659 is 9569861.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1689659 - 2²⁰ = 641083 is a prime.

Together with 1689661, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1680659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 844829 + 844830.

It is an arithmetic number, because the mean of its divisors is an integer number (844830).

2^1689659 is an apocalyptic number.

1689659 is a deficient number, since it is larger than the sum of its proper divisors (1).

1689659 is an equidigital number, since it uses as much as digits as its factorization.

1689659 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 116640, while the sum is 44.

The square root of 1689659 is about 1299.8688395373. The cubic root of 1689659 is about 119.1058305764.

The spelling of 1689659 in words is "one million, six hundred eighty-nine thousand, six hundred fifty-nine".