1221111222211 has 4 divisors (see below), whose sum is σ = 1224250326000. Its totient is φ = 1217972118424.

The previous prime is 1221111222209. The next prime is 1221111222251. The reversal of 1221111222211 is 1122221111221.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 1221111222211 - 2¹ = 1221111222209 is a prime.

It is a super-2 number, since 2×1221111222211² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221111222251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1569551311 + ... + 1569552088.

It is an arithmetic number, because the mean of its divisors is an integer number (306062581500).

Almost surely, 2^{1221111222211} is an apocalyptic number.

1221111222211 is a deficient number, since it is larger than the sum of its proper divisors (3139103789).

1221111222211 is an equidigital number, since it uses as much as digits as its factorization.

1221111222211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3139103788.

The product of its digits is 64, while the sum is 19.

Adding to 1221111222211 its reverse (1122221111221), we get a palindrome (2343332333432).

The spelling of 1221111222211 in words is "one trillion, two hundred twenty-one billion, one hundred eleven million, two hundred twenty-two thousand, two hundred eleven".