1222111221221 has 16 divisors (see below), whose sum is σ = 1379272233600. Its totient is φ = 1072631716800.

The previous prime is 1222111221209. The next prime is 1222111221301. The reversal of 1222111221221 is 1221221112221.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1222111221221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1222111221193 and 1222111221202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1222111221521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5317160 + ... + 5542238.

It is an arithmetic number, because the mean of its divisors is an integer number (86204514600).

Almost surely, 2^{1222111221221} is an apocalyptic number.

1222111221221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1222111221221 is a deficient number, since it is larger than the sum of its proper divisors (157161012379).

1222111221221 is a wasteful number, since it uses less digits than its factorization.

1222111221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242140.

The product of its digits is 128, while the sum is 20.

Adding to 1222111221221 its reverse (1221221112221), we get a palindrome (2443332333442).

The spelling of 1222111221221 in words is "one trillion, two hundred twenty-two billion, one hundred eleven million, two hundred twenty-one thousand, two hundred twenty-one".