12111999 has 4 divisors (see below), whose sum is σ = 16149336. Its totient is φ = 8074664.

The previous prime is 12111997. The next prime is 12112013. The reversal of 12111999 is 99911121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 99911121 = 3 ⋅33303707.

It is a cyclic number.

It is not a de Polignac number, because 12111999 - 2¹ = 12111997 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12111991) 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, 2018664 + ... + 2018669.

It is an arithmetic number, because the mean of its divisors is an integer number (4037334).

Almost surely, 2^12111999 is an apocalyptic number.

12111999 is a deficient number, since it is larger than the sum of its proper divisors (4037337).

12111999 is an equidigital number, since it uses as much as digits as its factorization.

12111999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4037336.

The product of its digits is 1458, while the sum is 33.

The square root of 12111999 is about 3480.2297337963. The cubic root of 12111999 is about 229.6529043086.

The spelling of 12111999 in words is "twelve million, one hundred eleven thousand, nine hundred ninety-nine".