12719809 has 2 divisors, whose sum is σ = 12719810. Its totient is φ = 12719808.

The previous prime is 12719807. The next prime is 12719821. The reversal of 12719809 is 90891721.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10870209 + 1849600 = 3297^2 + 1360^2 .

It is a cyclic number.

It is not a de Polignac number, because 12719809 - 2¹ = 12719807 is a prime.

Together with 12719807, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (12719803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6359904 + 6359905.

It is an arithmetic number, because the mean of its divisors is an integer number (6359905).

Almost surely, 2^12719809 is an apocalyptic number.

It is an amenable number.

12719809 is a deficient number, since it is larger than the sum of its proper divisors (1).

12719809 is an equidigital number, since it uses as much as digits as its factorization.

12719809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9072, while the sum is 37.

The square root of 12719809 is about 3566.4841230545. The cubic root of 12719809 is about 233.4318955487.

The spelling of 12719809 in words is "twelve million, seven hundred nineteen thousand, eight hundred nine".