1689397 has 2 divisors, whose sum is σ = 1689398. Its totient is φ = 1689396.

The previous prime is 1689379. The next prime is 1689431. The reversal of 1689397 is 7939861.

Together with previous prime (1689379) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 904401 + 784996 = 951^2 + 886^2 .

It is an emirp because it is prime and its reverse (7939861) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1689397 is a prime.

It is a d-powerful number, because it can be written as 1 + 6⁸ + 8 + 9² + 3⁸ + 9³ + 7⁴ .

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1689367) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 844698 + 844699.

It is an arithmetic number, because the mean of its divisors is an integer number (844699).

2^1689397 is an apocalyptic number.

It is an amenable number.

1689397 is a deficient number, since it is larger than the sum of its proper divisors (1).

1689397 is an equidigital number, since it uses as much as digits as its factorization.

1689397 is an evil number, because the sum of its binary digits is even.

The product of its digits is 81648, while the sum is 43.

The square root of 1689397 is about 1299.7680562316. The cubic root of 1689397 is about 119.0996740401.

The spelling of 1689397 in words is "one million, six hundred eighty-nine thousand, three hundred ninety-seven".