12006221 has 4 divisors (see below), whose sum is σ = 12013152. Its totient is φ = 11999292.

The previous prime is 12006217. The next prime is 12006223. The reversal of 12006221 is 12260021.

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 a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 12260021 = 349 ⋅35129.

It is a cyclic number.

It is not a de Polignac number, because 12006221 - 2² = 12006217 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12006196 and 12006205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12006223) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1730 + ... + 5196.

It is an arithmetic number, because the mean of its divisors is an integer number (3003288).

Almost surely, 2^12006221 is an apocalyptic number.

It is an amenable number.

12006221 is a deficient number, since it is larger than the sum of its proper divisors (6931).

12006221 is an equidigital number, since it uses as much as digits as its factorization.

12006221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6930.

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 12006221 is about 3464.9994227994. Note that the first 3 decimals coincide. The cubic root of 12006221 is about 228.9824042721.

Adding to 12006221 its reverse (12260021), we get a palindrome (24266242).

The spelling of 12006221 in words is "twelve million, six thousand, two hundred twenty-one".