21604226 has 32 divisors (see below), whose sum is σ = 38413440. Its totient is φ = 8919936.

The previous prime is 21604223. The next prime is 21604243. The reversal of 21604226 is 62240612.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21604223) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 92606 + ... + 92838.

It is an arithmetic number, because the mean of its divisors is an integer number (1200420).

Almost surely, 2^21604226 is an apocalyptic number.

21604226 is a deficient number, since it is larger than the sum of its proper divisors (16809214).

21604226 is a wasteful number, since it uses less digits than its factorization.

21604226 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 458.

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 21604226 is about 4648.0346384251. The cubic root of 21604226 is about 278.5134911976.

Adding to 21604226 its reverse (62240612), we get a palindrome (83844838).

The spelling of 21604226 in words is "twenty-one million, six hundred four thousand, two hundred twenty-six".