1688917 has 2 divisors, whose sum is σ = 1688918. Its totient is φ = 1688916.

The previous prime is 1688909. The next prime is 1688923. The reversal of 1688917 is 7198861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 938961 + 749956 = 969^2 + 866^2 .

It is a cyclic number.

It is not a de Polignac number, because 1688917 - 2³ = 1688909 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1688917.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1688927) 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, 844458 + 844459.

It is an arithmetic number, because the mean of its divisors is an integer number (844459).

2^1688917 is an apocalyptic number.

It is an amenable number.

1688917 is a deficient number, since it is larger than the sum of its proper divisors (1).

1688917 is an equidigital number, since it uses as much as digits as its factorization.

1688917 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24192, while the sum is 40.

The square root of 1688917 is about 1299.5833947847. The cubic root of 1688917 is about 119.0883932382.

The spelling of 1688917 in words is "one million, six hundred eighty-eight thousand, nine hundred seventeen".