11111232221 has 4 divisors (see below), whose sum is σ = 11111832444. Its totient is φ = 11110632000.

The previous prime is 11111232199. The next prime is 11111232227. The reversal of 11111232221 is 12223211111.

It is a happy number.

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 5514696121 + 5596536100 = 74261^2 + 74810^2 .

It is a cyclic number.

It is not a de Polignac number, because 11111232221 - 2⁶ = 11111232157 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 11111232221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11111232227) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 271430 + ... + 309671.

It is an arithmetic number, because the mean of its divisors is an integer number (2777958111).

Almost surely, 2^11111232221 is an apocalyptic number.

It is an amenable number.

11111232221 is a deficient number, since it is larger than the sum of its proper divisors (600223).

11111232221 is an equidigital number, since it uses as much as digits as its factorization.

11111232221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 600222.

The product of its digits is 48, while the sum is 17.

Adding to 11111232221 its reverse (12223211111), we get a palindrome (23334443332).

The spelling of 11111232221 in words is "eleven billion, one hundred eleven million, two hundred thirty-two thousand, two hundred twenty-one".