1121121212221 has 4 divisors (see below), whose sum is σ = 1121139763744. Its totient is φ = 1121102660700.

The previous prime is 1121121212219. The next prime is 1121121212227. The reversal of 1121121212221 is 1222121211211.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1121121212221 - 2¹ = 1121121212219 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1121121212227) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9184815 + ... + 9306076.

It is an arithmetic number, because the mean of its divisors is an integer number (280284940936).

Almost surely, 2^{1121121212221} is an apocalyptic number.

It is an amenable number.

1121121212221 is a deficient number, since it is larger than the sum of its proper divisors (18551523).

1121121212221 is an equidigital number, since it uses as much as digits as its factorization.

1121121212221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18551522.

The product of its digits is 64, while the sum is 19.

Adding to 1121121212221 its reverse (1222121211211), we get a palindrome (2343242423432).

The spelling of 1121121212221 in words is "one trillion, one hundred twenty-one billion, one hundred twenty-one million, two hundred twelve thousand, two hundred twenty-one".