12215591 has 2 divisors, whose sum is σ = 12215592. Its totient is φ = 12215590.

The previous prime is 12215579. The next prime is 12215611. The reversal of 12215591 is 19551221.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 12215591 - 2⁶ = 12215527 is a prime.

It is a Chen prime.

It is a plaindrome in base 15.

It is a self number, because there is not a number n which added to its sum of digits gives 12215591.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12215531) 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, 6107795 + 6107796.

It is an arithmetic number, because the mean of its divisors is an integer number (6107796).

Almost surely, 2^12215591 is an apocalyptic number.

12215591 is a deficient number, since it is larger than the sum of its proper divisors (1).

12215591 is an equidigital number, since it uses as much as digits as its factorization.

12215591 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 900, while the sum is 26.

The square root of 12215591 is about 3495.0809718803. The cubic root of 12215591 is about 230.3057747803.

The spelling of 12215591 in words is "twelve million, two hundred fifteen thousand, five hundred ninety-one".