11971409 has 2 divisors, whose sum is σ = 11971410. Its totient is φ = 11971408.

The previous prime is 11971397. The next prime is 11971411. The reversal of 11971409 is 90417911.

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., 6076225 + 5895184 = 2465^2 + 2428^2 .

It is a cyclic number.

It is not a de Polignac number, because 11971409 - 2¹² = 11967313 is a prime.

Together with 11971411, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p₇₈₆₃₀₈ and since 11971409 and 786308 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (11971439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5985704 + 5985705.

It is an arithmetic number, because the mean of its divisors is an integer number (5985705).

Almost surely, 2^11971409 is an apocalyptic number.

It is an amenable number.

11971409 is a deficient number, since it is larger than the sum of its proper divisors (1).

11971409 is an equidigital number, since it uses as much as digits as its factorization.

11971409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2268, while the sum is 32.

The square root of 11971409 is about 3459.9723987338. The cubic root of 11971409 is about 228.7608787763.

The spelling of 11971409 in words is "eleven million, nine hundred seventy-one thousand, four hundred nine".