12105221 has 4 divisors (see below), whose sum is σ = 12495744. Its totient is φ = 11714700.

The previous prime is 12105211. The next prime is 12105271. The reversal of 12105221 is 12250121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12250121 = 13 ⋅942317.

It is a cyclic number.

It is not a de Polignac number, because 12105221 - 2¹⁴ = 12088837 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12105196 and 12105205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12105211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 195215 + ... + 195276.

It is an arithmetic number, because the mean of its divisors is an integer number (3123936).

Almost surely, 2^12105221 is an apocalyptic number.

It is an amenable number.

12105221 is a deficient number, since it is larger than the sum of its proper divisors (390523).

12105221 is an equidigital number, since it uses as much as digits as its factorization.

12105221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390522.

The product of its (nonzero) digits is 40, while the sum is 14.

The square root of 12105221 is about 3479.2558112332. The cubic root of 12105221 is about 229.6100576011.

Adding to 12105221 its reverse (12250121), we get a palindrome (24355342).

The spelling of 12105221 in words is "twelve million, one hundred five thousand, two hundred twenty-one".