21204226 has 4 divisors (see below), whose sum is σ = 31806342. Its totient is φ = 10602112.

The previous prime is 21204223. The next prime is 21204241. The reversal of 21204226 is 62240212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 17598025 + 3606201 = 4195^2 + 1899^2 .

It is not an unprimeable number, because it can be changed into a prime (21204223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5301055 + ... + 5301058.

Almost surely, 2^21204226 is an apocalyptic number.

21204226 is a deficient number, since it is larger than the sum of its proper divisors (10602116).

21204226 is a wasteful number, since it uses less digits than its factorization.

21204226 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10602115.

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 21204226 is about 4604.8046646953. The cubic root of 21204226 is about 276.7838896172.

Adding to 21204226 its reverse (62240212), we get a palindrome (83444438).

The spelling of 21204226 in words is "twenty-one million, two hundred four thousand, two hundred twenty-six".