21223017 has 12 divisors (see below), whose sum is σ = 31025904. Its totient is φ = 13977720.

The previous prime is 21223009. The next prime is 21223051. The reversal of 21223017 is 71032212.

It is not a de Polignac number, because 21223017 - 2³ = 21223009 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21228017) 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 11 ways as a sum of consecutive naturals, for example, 13459 + ... + 14952.

It is an arithmetic number, because the mean of its divisors is an integer number (2585492).

Almost surely, 2^21223017 is an apocalyptic number.

It is an amenable number.

21223017 is a deficient number, since it is larger than the sum of its proper divisors (9802887).

21223017 is a wasteful number, since it uses less digits than its factorization.

21223017 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28500 (or 28497 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 18.

The square root of 21223017 is about 4606.8445817067. The cubic root of 21223017 is about 276.8656266328.

Adding to 21223017 its reverse (71032212), we get a palindrome (92255229).

The spelling of 21223017 in words is "twenty-one million, two hundred twenty-three thousand, seventeen".