12181217 has 2 divisors, whose sum is σ = 12181218. Its totient is φ = 12181216.

The previous prime is 12181207. The next prime is 12181243. The reversal of 12181217 is 71218121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7203856 + 4977361 = 2684^2 + 2231^2 .

It is a cyclic number.

It is not a de Polignac number, because 12181217 - 2¹⁶ = 12115681 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 12181192 and 12181201.

It is not a weakly prime, because it can be changed into another prime (12181207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6090608 + 6090609.

It is an arithmetic number, because the mean of its divisors is an integer number (6090609).

Almost surely, 2^12181217 is an apocalyptic number.

It is an amenable number.

12181217 is a deficient number, since it is larger than the sum of its proper divisors (1).

12181217 is an equidigital number, since it uses as much as digits as its factorization.

12181217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 224, while the sum is 23.

The square root of 12181217 is about 3490.1600249845. The cubic root of 12181217 is about 230.0895492509.

Adding to 12181217 its reverse (71218121), we get a palindrome (83399338).

The spelling of 12181217 in words is "twelve million, one hundred eighty-one thousand, two hundred seventeen".