1221111111101 has 16 divisors (see below), whose sum is σ = 1400992927488. Its totient is φ = 1042589385600.

The previous prime is 1221111111089. The next prime is 1221111111109. The reversal of 1221111111101 is 1011111111221.

It is not a de Polignac number, because 1221111111101 - 2²⁶ = 1221044002237 is a prime.

It is a super-2 number, since 2×1221111111101² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221111111109) 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, 25236191 + ... + 25284531.

It is an arithmetic number, because the mean of its divisors is an integer number (87562057968).

Almost surely, 2^{1221111111101} is an apocalyptic number.

It is an amenable number.

1221111111101 is a deficient number, since it is larger than the sum of its proper divisors (179881816387).

1221111111101 is a wasteful number, since it uses less digits than its factorization.

1221111111101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62332.

The product of its (nonzero) digits is 4, while the sum is 14.

Adding to 1221111111101 its reverse (1011111111221), we get a palindrome (2232222222322).

The spelling of 1221111111101 in words is "one trillion, two hundred twenty-one billion, one hundred eleven million, one hundred eleven thousand, one hundred one".