12221405 has 8 divisors (see below), whose sum is σ = 16760832. Its totient is φ = 8380368.

The previous prime is 12221401. The next prime is 12221413. The reversal of 12221405 is 50412221.

12221405 = 129² + 130² + ... + 338².

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 12221405 - 2² = 12221401 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12221401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 174557 + ... + 174626.

It is an arithmetic number, because the mean of its divisors is an integer number (2095104).

Almost surely, 2^12221405 is an apocalyptic number.

It is an amenable number.

12221405 is a deficient number, since it is larger than the sum of its proper divisors (4539427).

12221405 is an equidigital number, since it uses as much as digits as its factorization.

12221405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 349195.

The product of its (nonzero) digits is 160, while the sum is 17.

The square root of 12221405 is about 3495.9126133243. The cubic root of 12221405 is about 230.3423069301.

Adding to 12221405 its reverse (50412221), we get a palindrome (62633626).

The spelling of 12221405 in words is "twelve million, two hundred twenty-one thousand, four hundred five".