21223366 has 8 divisors (see below), whose sum is σ = 31857984. Its totient is φ = 10604040.

The previous prime is 21223357. The next prime is 21223369. The reversal of 21223366 is 66332212.

It is a happy number.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21223366.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21223369) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 736 + ... + 6556.

It is an arithmetic number, because the mean of its divisors is an integer number (3982248).

Almost surely, 2^21223366 is an apocalyptic number.

21223366 is a deficient number, since it is larger than the sum of its proper divisors (10634618).

21223366 is a wasteful number, since it uses less digits than its factorization.

21223366 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7646.

The product of its digits is 2592, while the sum is 25.

The square root of 21223366 is about 4606.8824599723. The cubic root of 21223366 is about 276.8671442551.

Adding to 21223366 its reverse (66332212), we get a palindrome (87555578).

The spelling of 21223366 in words is "twenty-one million, two hundred twenty-three thousand, three hundred sixty-six".