1211111221110 has 128 divisors (see below), whose sum is σ = 3358112808960. Its totient is φ = 273814459776.

The previous prime is 1211111221051. The next prime is 1211111221171. The reversal of 1211111221110 is 111221111121.

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 1211111221110.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 18547579 + ... + 18612761.

It is an arithmetic number, because the mean of its divisors is an integer number (26235256320).

Almost surely, 2^{1211111221110} is an apocalyptic number.

1211111221110 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1211111221110, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1679056404480).

1211111221110 is an abundant number, since it is smaller than the sum of its proper divisors (2147001587850).

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

1211111221110 is a wasteful number, since it uses less digits than its factorization.

1211111221110 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66162.

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

Adding to 1211111221110 its reverse (111221111121), we get a palindrome (1322332332231).

The spelling of 1211111221110 in words is "one trillion, two hundred eleven billion, one hundred eleven million, two hundred twenty-one thousand, one hundred ten".