21223533 has 16 divisors (see below), whose sum is σ = 29483136. Its totient is φ = 13567680.

The previous prime is 21223519. The next prime is 21223583. The reversal of 21223533 is 33532212.

It is not a de Polignac number, because 21223533 - 2⁸ = 21223277 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21223583) 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 15 ways as a sum of consecutive naturals, for example, 6535 + ... + 9227.

It is an arithmetic number, because the mean of its divisors is an integer number (1842696).

Almost surely, 2^21223533 is an apocalyptic number.

It is an amenable number.

21223533 is a deficient number, since it is larger than the sum of its proper divisors (8259603).

21223533 is a wasteful number, since it uses less digits than its factorization.

21223533 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2804.

The product of its digits is 1080, while the sum is 21.

The square root of 21223533 is about 4606.9005849920. The cubic root of 21223533 is about 276.8678704468.

Adding to 21223533 its reverse (33532212), we get a palindrome (54755745).

The spelling of 21223533 in words is "twenty-one million, two hundred twenty-three thousand, five hundred thirty-three".