121111221111221 has 32 divisors (see below), whose sum is σ = 135269852276736. Its totient is φ = 107497713960000.

The previous prime is 121111221111191. The next prime is 121111221111247. The reversal of 121111221111221 is 122111122111121.

It is a cyclic number.

It is not a de Polignac number, because 121111221111221 - 2¹⁰ = 121111221110197 is a prime.

It is a super-2 number, since 2×121111221111221² (a number of 29 digits) contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 121111221111193 and 121111221111202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121111221111271) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1004586896 + ... + 1004707446.

It is an arithmetic number, because the mean of its divisors is an integer number (4227182883648).

Almost surely, 2^{121111221111221} is an apocalyptic number.

121111221111221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

121111221111221 is a deficient number, since it is larger than the sum of its proper divisors (14158631165515).

121111221111221 is a wasteful number, since it uses less digits than its factorization.

121111221111221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128993.

The product of its digits is 32, while the sum is 20.

Adding to 121111221111221 its reverse (122111122111121), we get a palindrome (243222343222342).

The spelling of 121111221111221 in words is "one hundred twenty-one trillion, one hundred eleven billion, two hundred twenty-one million, one hundred eleven thousand, two hundred twenty-one".