1220121211111 has 16 divisors (see below), whose sum is σ = 1355806615680. Its totient is φ = 1088753568480.

The previous prime is 1220121211097. The next prime is 1220121211117. The reversal of 1220121211111 is 1111121210221.

It is a cyclic number.

It is not a de Polignac number, because 1220121211111 - 2⁵ = 1220121211079 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220121211117) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4626921 + ... + 4883506.

It is an arithmetic number, because the mean of its divisors is an integer number (84737913480).

Almost surely, 2^{1220121211111} is an apocalyptic number.

1220121211111 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1220121211111 is a deficient number, since it is larger than the sum of its proper divisors (135685404569).

1220121211111 is a wasteful number, since it uses less digits than its factorization.

1220121211111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9510654.

The product of its (nonzero) digits is 16, while the sum is 16.

Adding to 1220121211111 its reverse (1111121210221), we get a palindrome (2331242421332).

The spelling of 1220121211111 in words is "one trillion, two hundred twenty billion, one hundred twenty-one million, two hundred eleven thousand, one hundred eleven".