12278909 has 2 divisors, whose sum is σ = 12278910. Its totient is φ = 12278908.

The previous prime is 12278887. The next prime is 12278911. The reversal of 12278909 is 90987221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11035684 + 1243225 = 3322^2 + 1115^2 .

It is a cyclic number.

It is not a de Polignac number, because 12278909 - 2¹² = 12274813 is a prime.

Together with 12278911, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12278989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6139454 + 6139455.

It is an arithmetic number, because the mean of its divisors is an integer number (6139455).

Almost surely, 2^12278909 is an apocalyptic number.

It is an amenable number.

12278909 is a deficient number, since it is larger than the sum of its proper divisors (1).

12278909 is an equidigital number, since it uses as much as digits as its factorization.

12278909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18144, while the sum is 38.

The square root of 12278909 is about 3504.1274234822. The cubic root of 12278909 is about 230.7030096972.

The spelling of 12278909 in words is "twelve million, two hundred seventy-eight thousand, nine hundred nine".