11211221 has 8 divisors (see below), whose sum is σ = 12837504. Its totient is φ = 9591120.

The previous prime is 11211217. The next prime is 11211229. The reversal of 11211221 is 12211211.

11211221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 11211221 - 2² = 11211217 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11211229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3416 + ... + 5838.

It is an arithmetic number, because the mean of its divisors is an integer number (1604688).

Almost surely, 2^11211221 is an apocalyptic number.

It is an amenable number.

11211221 is a deficient number, since it is larger than the sum of its proper divisors (1626283).

11211221 is an equidigital number, since it uses as much as digits as its factorization.

11211221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3091.

The product of its digits is 8, while the sum is 11.

The square root of 11211221 is about 3348.3161439745. The cubic root of 11211221 is about 223.8124825760.

Adding to 11211221 its reverse (12211211), we get a palindrome (23422432).

The spelling of 11211221 in words is "eleven million, two hundred eleven thousand, two hundred twenty-one".