12222121 has 2 divisors, whose sum is σ = 12222122.
Its totient is φ = 12222120.
The previous prime is 12222109. The next prime is 12222127. The reversal of 12222121 is 12122221.
Adding to 12222121 its reverse (12122221), we get a palindrome (24344342).
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., 11806096 + 416025 = 3436^2 + 645^2
It is an emirp because it is prime and its reverse (12122221) is a distict prime.
It is a cyclic number.
It is not a de Polignac number, because 12222121 - 221 = 10124969 is a prime.
It is a Chen prime.
It is not a weakly prime, because it can be changed into another prime (12222127) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6111060 + 6111061.
It is an arithmetic number, because the mean of its divisors is an integer number (6111061).
Almost surely, 212222121 is an apocalyptic number.
It is an amenable number.
12222121 is a deficient number, since it is larger than the sum of its proper divisors (1).
12222121 is an equidigital number, since it uses as much as digits as its factorization.
12222121 is an odious number, because the sum of its binary digits is odd.
The product of its digits is 32, while the sum is 13.
The square root of 12222121 is about 3496.0150171302.
The cubic root of 12222121 is about 230.3468051001.
The spelling of 12222121 in words is "twelve million, two hundred twenty-two thousand, one hundred twenty-one".