21323206 has 16 divisors (see below), whose sum is σ = 34099200. Its totient is φ = 9971208.

The previous prime is 21323191. The next prime is 21323209. The reversal of 21323206 is 60232312.

It is a super-2 number, since 2×21323206² = 909358228236872, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21323209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 550 + ... + 6553.

It is an arithmetic number, because the mean of its divisors is an integer number (2131200).

Almost surely, 2^21323206 is an apocalyptic number.

21323206 is a deficient number, since it is larger than the sum of its proper divisors (12775994).

21323206 is a wasteful number, since it uses less digits than its factorization.

21323206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7203.

The product of its (nonzero) digits is 432, while the sum is 19.

The square root of 21323206 is about 4617.7057073833. The cubic root of 21323206 is about 277.3006159141.

Adding to 21323206 its reverse (60232312), we get a palindrome (81555518).

The spelling of 21323206 in words is "twenty-one million, three hundred twenty-three thousand, two hundred six".