21111199 has 2 divisors, whose sum is σ = 21111200. Its totient is φ = 21111198.

The previous prime is 21111197. The next prime is 21111239. The reversal of 21111199 is 99111112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21111199 - 2¹ = 21111197 is a prime.

Together with 21111197, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21111191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555599 + 10555600.

It is an arithmetic number, because the mean of its divisors is an integer number (10555600).

Almost surely, 2^21111199 is an apocalyptic number.

21111199 is a deficient number, since it is larger than the sum of its proper divisors (1).

21111199 is an equidigital number, since it uses as much as digits as its factorization.

21111199 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 162, while the sum is 25.

The square root of 21111199 is about 4594.6924815487. The cubic root of 21111199 is about 276.3785282631.

The spelling of 21111199 in words is "twenty-one million, one hundred eleven thousand, one hundred ninety-nine".