11021221 has 4 divisors (see below), whose sum is σ = 11130444. Its totient is φ = 10912000.

The previous prime is 11021183. The next prime is 11021249. The reversal of 11021221 is 12212011.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7452900 + 3568321 = 2730^2 + 1889^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11021221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 11021198 and 11021207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11021261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 54460 + ... + 54661.

It is an arithmetic number, because the mean of its divisors is an integer number (2782611).

Almost surely, 2^11021221 is an apocalyptic number.

It is an amenable number.

11021221 is a deficient number, since it is larger than the sum of its proper divisors (109223).

11021221 is a wasteful number, since it uses less digits than its factorization.

11021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109222.

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 11021221 is about 3319.8224350106. The cubic root of 11021221 is about 222.5409325863.

Adding to 11021221 its reverse (12212011), we get a palindrome (23233232).

The spelling of 11021221 in words is "eleven million, twenty-one thousand, two hundred twenty-one".