21223603 has 2 divisors, whose sum is σ = 21223604. Its totient is φ = 21223602.

The previous prime is 21223583. The next prime is 21223613. The reversal of 21223603 is 30632212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21223603 - 2⁹ = 21223091 is a prime.

It is not a weakly prime, because it can be changed into another prime (21223613) 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 as a sum of consecutive naturals, namely, 10611801 + 10611802.

It is an arithmetic number, because the mean of its divisors is an integer number (10611802).

Almost surely, 2^21223603 is an apocalyptic number.

21223603 is a deficient number, since it is larger than the sum of its proper divisors (1).

21223603 is an equidigital number, since it uses as much as digits as its factorization.

21223603 is an odious number, because the sum of its binary digits is odd.

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

The square root of 21223603 is about 4606.9081822845. The cubic root of 21223603 is about 276.8681748373.

Adding to 21223603 its reverse (30632212), we get a palindrome (51855815).

The spelling of 21223603 in words is "twenty-one million, two hundred twenty-three thousand, six hundred three".