11112221 has 4 divisors (see below), whose sum is σ = 11119200. Its totient is φ = 11105244.

The previous prime is 11112217. The next prime is 11112239. The reversal of 11112221 is 12221111.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 11112221 - 2² = 11112217 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 (11112251) 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 3 ways as a sum of consecutive naturals, for example, 200 + ... + 4718.

It is an arithmetic number, because the mean of its divisors is an integer number (2779800).

Almost surely, 2^11112221 is an apocalyptic number.

It is an amenable number.

11112221 is a deficient number, since it is larger than the sum of its proper divisors (6979).

11112221 is an equidigital number, since it uses as much as digits as its factorization.

11112221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6978.

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

The square root of 11112221 is about 3333.4998125094. The cubic root of 11112221 is about 223.1517464086.

Adding to 11112221 its reverse (12221111), we get a palindrome (23333332).

It can be divided in two parts, 1111 and 2221, that multiplied together give a triangular number (2467531 = T₂₂₂₁).

The spelling of 11112221 in words is "eleven million, one hundred twelve thousand, two hundred twenty-one".