12111818 has 4 divisors (see below), whose sum is σ = 18167730. Its totient is φ = 6055908.

The previous prime is 12111817. The next prime is 12111829. The reversal of 12111818 is 81811121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 81811121 = 7 ⋅11687303.

It can be written as a sum of positive squares in only one way, i.e., 9840769 + 2271049 = 3137^2 + 1507^2 .

It is a super-2 number, since 2×12111818² = 293392270530248, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 12111793 and 12111802.

It is not an unprimeable number, because it can be changed into a prime (12111811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3027953 + ... + 3027956.

Almost surely, 2^12111818 is an apocalyptic number.

12111818 is a deficient number, since it is larger than the sum of its proper divisors (6055912).

12111818 is an equidigital number, since it uses as much as digits as its factorization.

12111818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6055911.

The product of its digits is 128, while the sum is 23.

The square root of 12111818 is about 3480.2037296687. The cubic root of 12111818 is about 229.6517603361.

Adding to 12111818 its reverse (81811121), we get a palindrome (93922939).

The spelling of 12111818 in words is "twelve million, one hundred eleven thousand, eight hundred eighteen".