21986233 has 2 divisors, whose sum is σ = 21986234. Its totient is φ = 21986232.

The previous prime is 21986231. The next prime is 21986243. The reversal of 21986233 is 33268912.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20539024 + 1447209 = 4532^2 + 1203^2 .

It is a cyclic number.

It is not a de Polignac number, because 21986233 - 2¹ = 21986231 is a prime.

Together with 21986231, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21986231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10993116 + 10993117.

It is an arithmetic number, because the mean of its divisors is an integer number (10993117).

Almost surely, 2^21986233 is an apocalyptic number.

It is an amenable number.

21986233 is a deficient number, since it is larger than the sum of its proper divisors (1).

21986233 is an equidigital number, since it uses as much as digits as its factorization.

21986233 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15552, while the sum is 34.

The square root of 21986233 is about 4688.9479630297. The cubic root of 21986233 is about 280.1454728764.

The spelling of 21986233 in words is "twenty-one million, nine hundred eighty-six thousand, two hundred thirty-three".