1221122211 has 16 divisors (see below), whose sum is σ = 1679568384. Its totient is φ = 788573664.

The previous prime is 1221122207. The next prime is 1221122239. The reversal of 1221122211 is 1122211221.

It is not a de Polignac number, because 1221122211 - 2² = 1221122207 is a prime.

It is a super-2 number, since 2×1221122211² = 2982278908395057042, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1221122281) 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 15 ways as a sum of consecutive naturals, for example, 966 + ... + 49428.

It is an arithmetic number, because the mean of its divisors is an integer number (104973024).

Almost surely, 2^1221122211 is an apocalyptic number.

1221122211 is a deficient number, since it is larger than the sum of its proper divisors (458446173).

1221122211 is a wasteful number, since it uses less digits than its factorization.

1221122211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48730.

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

The square root of 1221122211 is about 34944.5591043871. The cubic root of 1221122211 is about 1068.8572570171.

Adding to 1221122211 its reverse (1122211221), we get a palindrome (2343333432).

The spelling of 1221122211 in words is "one billion, two hundred twenty-one million, one hundred twenty-two thousand, two hundred eleven".