12840689 has 2 divisors, whose sum is σ = 12840690. Its totient is φ = 12840688.

The previous prime is 12840679. The next prime is 12840691. The reversal of 12840689 is 98604821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6630625 + 6210064 = 2575^2 + 2492^2 .

It is a cyclic number.

It is not a de Polignac number, because 12840689 - 2¹⁶ = 12775153 is a prime.

Together with 12840691, 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 (12840679) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6420344 + 6420345.

It is an arithmetic number, because the mean of its divisors is an integer number (6420345).

Almost surely, 2^12840689 is an apocalyptic number.

It is an amenable number.

12840689 is a deficient number, since it is larger than the sum of its proper divisors (1).

12840689 is an equidigital number, since it uses as much as digits as its factorization.

12840689 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27648, while the sum is 38.

The square root of 12840689 is about 3583.3907127189. The cubic root of 12840689 is about 234.1690222081.

The spelling of 12840689 in words is "twelve million, eight hundred forty thousand, six hundred eighty-nine".