1211221111110 has 32 divisors (see below), whose sum is σ = 2908326366720. Its totient is φ = 322837218528.

The previous prime is 1211221111109. The next prime is 1211221111117. The reversal of 1211221111110 is 111111221121.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 1211221111110.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211221111117) 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 15 ways as a sum of consecutive naturals, for example, 9628830 + ... + 9753809.

It is an arithmetic number, because the mean of its divisors is an integer number (90885198960).

Almost surely, 2^{1211221111110} is an apocalyptic number.

1211221111110 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1211221111110 is an abundant number, since it is smaller than the sum of its proper divisors (1697105255610).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1211221111110 is a wasteful number, since it uses less digits than its factorization.

1211221111110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19384732.

The product of its (nonzero) digits is 8, while the sum is 15.

Adding to 1211221111110 its reverse (111111221121), we get a palindrome (1322332332231).

The spelling of 1211221111110 in words is "one trillion, two hundred eleven billion, two hundred twenty-one million, one hundred eleven thousand, one hundred ten".