12021121111 has 4 divisors (see below), whose sum is σ = 12022241824. Its totient is φ = 12020000400.

The previous prime is 12021121109. The next prime is 12021121127. The reversal of 12021121111 is 11112112021.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11112112021 = 293 ⋅37925297.

It is a cyclic number.

It is not a de Polignac number, because 12021121111 - 2¹ = 12021121109 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12021121091 and 12021121100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12021121181) 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, 544110 + ... + 565771.

It is an arithmetic number, because the mean of its divisors is an integer number (3005560456).

Almost surely, 2^12021121111 is an apocalyptic number.

12021121111 is a deficient number, since it is larger than the sum of its proper divisors (1120713).

12021121111 is a wasteful number, since it uses less digits than its factorization.

12021121111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1120712.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 12021121111 its reverse (11112112021), we get a palindrome (23133233132).

The spelling of 12021121111 in words is "twelve billion, twenty-one million, one hundred twenty-one thousand, one hundred eleven".