21533323 has 8 divisors (see below), whose sum is σ = 25210080. Its totient is φ = 18006720.

The previous prime is 21533293. The next prime is 21533333. The reversal of 21533323 is 32333512.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21533323 - 2⁹ = 21532811 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21533294 and 21533303.

It is not an unprimeable number, because it can be changed into a prime (21533333) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37228 + ... + 37801.

It is an arithmetic number, because the mean of its divisors is an integer number (3151260).

Almost surely, 2^21533323 is an apocalyptic number.

21533323 is a deficient number, since it is larger than the sum of its proper divisors (3676757).

21533323 is an equidigital number, since it uses as much as digits as its factorization.

21533323 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75077.

The product of its digits is 1620, while the sum is 22.

The square root of 21533323 is about 4640.4011680026. The cubic root of 21533323 is about 278.2084724077.

Adding to 21533323 its reverse (32333512), we get a palindrome (53866835).

It can be divided in two parts, 2153 and 3323, that added together give a square (5476 = 74²).

The spelling of 21533323 in words is "twenty-one million, five hundred thirty-three thousand, three hundred twenty-three".