12211999 has 4 divisors (see below), whose sum is σ = 12227560. Its totient is φ = 12196440.

The previous prime is 12211981. The next prime is 12212021. The reversal of 12211999 is 99911221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 99911221 = 79 ⋅1264699.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12211999 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12211909) 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, 6537 + ... + 8194.

It is an arithmetic number, because the mean of its divisors is an integer number (3056890).

Almost surely, 2^12211999 is an apocalyptic number.

12211999 is a deficient number, since it is larger than the sum of its proper divisors (15561).

12211999 is an equidigital number, since it uses as much as digits as its factorization.

12211999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15560.

The product of its digits is 2916, while the sum is 34.

The square root of 12211999 is about 3494.5670690373. The cubic root of 12211999 is about 230.2831987287.

It can be divided in two parts, 122 and 11999, that added together give a palindrome (12121).

The spelling of 12211999 in words is "twelve million, two hundred eleven thousand, nine hundred ninety-nine".