1211222221111 has 12 divisors (see below), whose sum is σ = 1408993918920. Its totient is φ = 1038174905040.

The previous prime is 1211222221103. The next prime is 1211222221117. The reversal of 1211222221111 is 1111222221121.

It is a happy number.

It is not a de Polignac number, because 1211222221111 - 2³ = 1211222221103 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211222221117) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4130001 + ... + 4413541.

It is an arithmetic number, because the mean of its divisors is an integer number (117416159910).

Almost surely, 2^{1211222221111} is an apocalyptic number.

1211222221111 is a deficient number, since it is larger than the sum of its proper divisors (197771697809).

1211222221111 is an equidigital number, since it uses as much as digits as its factorization.

1211222221111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 370734 (or 370727 counting only the distinct ones).

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

Adding to 1211222221111 its reverse (1111222221121), we get a palindrome (2322444442232).

The spelling of 1211222221111 in words is "one trillion, two hundred eleven billion, two hundred twenty-two million, two hundred twenty-one thousand, one hundred eleven".