12221121 has 24 divisors (see below), whose sum is σ = 18117792. Its totient is φ = 7321600.

The previous prime is 12221117. The next prime is 12221171. The reversal of 12221121 is 12112221.

It is not a de Polignac number, because 12221121 - 2² = 12221117 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 12221097 and 12221106.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12221171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 47425 + ... + 47681.

It is an arithmetic number, because the mean of its divisors is an integer number (754908).

Almost surely, 2^12221121 is an apocalyptic number.

12221121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12221121 is a deficient number, since it is larger than the sum of its proper divisors (5896671).

12221121 is a wasteful number, since it uses less digits than its factorization.

12221121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 413 (or 402 counting only the distinct ones).

The product of its digits is 16, while the sum is 12.

The square root of 12221121 is about 3495.8719942240. The cubic root of 12221121 is about 230.3405226911.

Adding to 12221121 its reverse (12112221), we get a palindrome (24333342).

Subtracting from 12221121 its reverse (12112221), we obtain a square (108900 = 330²).

It can be divided in two parts, 12221 and 121, that multiplied together give a palindrome (1478741).

The spelling of 12221121 in words is "twelve million, two hundred twenty-one thousand, one hundred twenty-one".