12111122121 has 16 divisors (see below), whose sum is σ = 19257437184. Its totient is φ = 6619743504.

The previous prime is 12111122119. The next prime is 12111122123. The reversal of 12111122121 is 12122111121.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (12111122119) and next prime (12111122123).

It is not a de Polignac number, because 12111122121 - 2¹ = 12111122119 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12111122121.

It is not an unprimeable number, because it can be changed into a prime (12111122123) 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, 12536911 + ... + 12537876.

It is an arithmetic number, because the mean of its divisors is an integer number (1203589824).

Almost surely, 2^12111122121 is an apocalyptic number.

It is an amenable number.

12111122121 is a deficient number, since it is larger than the sum of its proper divisors (7146315063).

12111122121 is a wasteful number, since it uses less digits than its factorization.

12111122121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25074820.

The product of its digits is 16, while the sum is 15.

Adding to 12111122121 its reverse (12122111121), we get a palindrome (24233233242).

It can be divided in two parts, 1211 and 1122121, that multiplied together give a palindrome (1358888531).

The spelling of 12111122121 in words is "twelve billion, one hundred eleven million, one hundred twenty-two thousand, one hundred twenty-one".