21221433233 has 16 divisors (see below), whose sum is σ = 28493114496. Its totient is φ = 15264167040.

The previous prime is 21221433209. The next prime is 21221433239. The reversal of 21221433233 is 33233412212.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21221433233 - 2¹⁰ = 21221432209 is a prime.

It is a Smith number, since the sum of its digits (26) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (21221433239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10599116 + ... + 10601117.

It is an arithmetic number, because the mean of its divisors is an integer number (1780819656).

Almost surely, 2^21221433233 is an apocalyptic number.

It is an amenable number.

21221433233 is a deficient number, since it is larger than the sum of its proper divisors (7271681263).

21221433233 is a wasteful number, since it uses less digits than its factorization.

21221433233 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21200264.

The product of its digits is 5184, while the sum is 26.

Adding to 21221433233 its reverse (33233412212), we get a palindrome (54454845445).

It can be divided in two parts, 21221 and 433233, that added together give a palindrome (454454).

The spelling of 21221433233 in words is "twenty-one billion, two hundred twenty-one million, four hundred thirty-three thousand, two hundred thirty-three".