12291809 has 2 divisors, whose sum is σ = 12291810. Its totient is φ = 12291808.

The previous prime is 12291793. The next prime is 12291817. The reversal of 12291809 is 90819221.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8880400 + 3411409 = 2980^2 + 1847^2 .

It is a cyclic number.

It is not a de Polignac number, because 12291809 - 2⁴ = 12291793 is a prime.

It is not a weakly prime, because it can be changed into another prime (12291859) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6145904 + 6145905.

It is an arithmetic number, because the mean of its divisors is an integer number (6145905).

Almost surely, 2^12291809 is an apocalyptic number.

It is an amenable number.

12291809 is a deficient number, since it is larger than the sum of its proper divisors (1).

12291809 is an equidigital number, since it uses as much as digits as its factorization.

12291809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 32.

The square root of 12291809 is about 3505.9676267758. The cubic root of 12291809 is about 230.7837722261.

The spelling of 12291809 in words is "twelve million, two hundred ninety-one thousand, eight hundred nine".