1221222111 has 8 divisors (see below), whose sum is σ = 1672304304. Its totient is φ = 792144000.

The previous prime is 1221222089. The next prime is 1221222113. The reversal of 1221222111 is 1112221221.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1221222111 - 2⁷ = 1221221983 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221222113) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5500890 + ... + 5501111.

It is an arithmetic number, because the mean of its divisors is an integer number (209038038).

Almost surely, 2^1221222111 is an apocalyptic number.

1221222111 is a deficient number, since it is larger than the sum of its proper divisors (451082193).

1221222111 is a wasteful number, since it uses less digits than its factorization.

1221222111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11002041.

The product of its digits is 32, while the sum is 15.

The square root of 1221222111 is about 34945.9884822278. The cubic root of 1221222111 is about 1068.8864039574.

Adding to 1221222111 its reverse (1112221221), we get a palindrome (2333443332).

The spelling of 1221222111 in words is "one billion, two hundred twenty-one million, two hundred twenty-two thousand, one hundred eleven".