1221111233 has 4 divisors (see below), whose sum is σ = 1222054020. Its totient is φ = 1220168448.

The previous prime is 1221111167. The next prime is 1221111253. The reversal of 1221111233 is 3321111221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3321111221 = 39821 ⋅83401.

It can be written as a sum of positive squares in 2 ways, for example, as 1206311824 + 14799409 = 34732^2 + 3847^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221111233 - 2¹⁸ = 1220849089 is a prime.

It is a super-2 number, since 2×1221111233² = 2982225286717560578, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221111253) 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, 469448 + ... + 472041.

It is an arithmetic number, because the mean of its divisors is an integer number (305513505).

Almost surely, 2^1221111233 is an apocalyptic number.

It is an amenable number.

1221111233 is a deficient number, since it is larger than the sum of its proper divisors (942787).

1221111233 is an equidigital number, since it uses as much as digits as its factorization.

1221111233 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 942786.

The product of its digits is 72, while the sum is 17.

The square root of 1221111233 is about 34944.4020266480. The cubic root of 1221111233 is about 1068.8540539661.

Adding to 1221111233 its reverse (3321111221), we get a palindrome (4542222454).

The spelling of 1221111233 in words is "one billion, two hundred twenty-one million, one hundred eleven thousand, two hundred thirty-three".