21236206 has 8 divisors (see below), whose sum is σ = 32016600. Its totient is φ = 10564008.

The previous prime is 21236161. The next prime is 21236219. The reversal of 21236206 is 60263212.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 26556 + ... + 27343.

It is an arithmetic number, because the mean of its divisors is an integer number (4002075).

Almost surely, 2^21236206 is an apocalyptic number.

21236206 is a deficient number, since it is larger than the sum of its proper divisors (10780394).

21236206 is a wasteful number, since it uses less digits than its factorization.

21236206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54098.

The product of its (nonzero) digits is 864, while the sum is 22.

The square root of 21236206 is about 4608.2758163981. The cubic root of 21236206 is about 276.9229672800.

Adding to 21236206 its reverse (60263212), we get a palindrome (81499418).

The spelling of 21236206 in words is "twenty-one million, two hundred thirty-six thousand, two hundred six".