12102121111 has 4 divisors (see below), whose sum is σ = 12383565832. Its totient is φ = 11820676392.

The previous prime is 12102121099. The next prime is 12102121127. The reversal of 12102121111 is 11112120121.

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: 11112120121 = 59 ⋅188341019.

It is a cyclic number.

It is not a de Polignac number, because 12102121111 - 2¹⁵ = 12102088343 is a prime.

It is a super-2 number, since 2×12102121111² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12102121091 and 12102121100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12102121511) 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, 140722296 + ... + 140722381.

It is an arithmetic number, because the mean of its divisors is an integer number (3095891458).

Almost surely, 2^12102121111 is an apocalyptic number.

12102121111 is a deficient number, since it is larger than the sum of its proper divisors (281444721).

12102121111 is an equidigital number, since it uses as much as digits as its factorization.

12102121111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 281444720.

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

Adding to 12102121111 its reverse (11112120121), we get a palindrome (23214241232).

The spelling of 12102121111 in words is "twelve billion, one hundred two million, one hundred twenty-one thousand, one hundred eleven".