21432199 has 2 divisors, whose sum is σ = 21432200. Its totient is φ = 21432198.

The previous prime is 21432197. The next prime is 21432211. The reversal of 21432199 is 99123412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21432199 - 2¹ = 21432197 is a prime.

Together with 21432197, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21432199.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21432197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10716099 + 10716100.

It is an arithmetic number, because the mean of its divisors is an integer number (10716100).

Almost surely, 2^21432199 is an apocalyptic number.

21432199 is a deficient number, since it is larger than the sum of its proper divisors (1).

21432199 is an equidigital number, since it uses as much as digits as its factorization.

21432199 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3888, while the sum is 31.

The square root of 21432199 is about 4629.4923047781. The cubic root of 21432199 is about 277.7722847566.

The spelling of 21432199 in words is "twenty-one million, four hundred thirty-two thousand, one hundred ninety-nine".