12127221 has 6 divisors (see below), whose sum is σ = 17517110. Its totient is φ = 8084808.

The previous prime is 12127217. The next prime is 12127223. The reversal of 12127221 is 12272121.

It is a happy number.

12127221 is nontrivially palindromic in base 14.

It can be written as a sum of positive squares in only one way, i.e., 10400625 + 1726596 = 3225^2 + 1314^2 .

It is not a de Polignac number, because 12127221 - 2² = 12127217 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12127194 and 12127203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12127223) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 673726 + ... + 673743.

Almost surely, 2^12127221 is an apocalyptic number.

It is an amenable number.

12127221 is a deficient number, since it is larger than the sum of its proper divisors (5389889).

12127221 is a wasteful number, since it uses less digits than its factorization.

12127221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1347475 (or 1347472 counting only the distinct ones).

The product of its digits is 112, while the sum is 18.

The square root of 12127221 is about 3482.4159717070. The cubic root of 12127221 is about 229.7490710126.

Adding to 12127221 its reverse (12272121), we get a palindrome (24399342).

The spelling of 12127221 in words is "twelve million, one hundred twenty-seven thousand, two hundred twenty-one".