11221221 has 8 divisors (see below), whose sum is σ = 16321824. Its totient is φ = 6800720.

The previous prime is 11221219. The next prime is 11221247. The reversal of 11221221 is 12212211.

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 11221221 - 2¹ = 11221219 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 11221197 and 11221206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11221211) 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 7 ways as a sum of consecutive naturals, for example, 169986 + ... + 170051.

It is an arithmetic number, because the mean of its divisors is an integer number (2040228).

Almost surely, 2^11221221 is an apocalyptic number.

11221221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

11221221 is a deficient number, since it is larger than the sum of its proper divisors (5100603).

11221221 is a wasteful number, since it uses less digits than its factorization.

11221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 340051.

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

The square root of 11221221 is about 3349.8090990383. The cubic root of 11221221 is about 223.8790069898.

Adding to 11221221 its reverse (12212211), we get a palindrome (23433432).

The spelling of 11221221 in words is "eleven million, two hundred twenty-one thousand, two hundred twenty-one".