1688231 has 2 divisors, whose sum is σ = 1688232. Its totient is φ = 1688230.

The previous prime is 1688213. The next prime is 1688237. The reversal of 1688231 is 1328861.

Together with previous prime (1688213) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is an emirp because it is prime and its reverse (1328861) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1688231 is a prime.

It is a super-2 number, since 2×1688231² = 5700247818722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 1688194 and 1688203.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1688237) 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, 844115 + 844116.

It is an arithmetic number, because the mean of its divisors is an integer number (844116).

2^1688231 is an apocalyptic number.

1688231 is a deficient number, since it is larger than the sum of its proper divisors (1).

1688231 is an equidigital number, since it uses as much as digits as its factorization.

1688231 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2304, while the sum is 29.

The square root of 1688231 is about 1299.3194372440. The cubic root of 1688231 is about 119.0722673814.

The spelling of 1688231 in words is "one million, six hundred eighty-eight thousand, two hundred thirty-one".