21323323 has 16 divisors (see below), whose sum is σ = 26311680. Its totient is φ = 16875936.

The previous prime is 21323311. The next prime is 21323371. The reversal of 21323323 is 32332312.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-21323323 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21323323.

It is not an unprimeable number, because it can be changed into a prime (21320323) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2386 + ... + 6952.

It is an arithmetic number, because the mean of its divisors is an integer number (1644480).

Almost surely, 2^21323323 is an apocalyptic number.

21323323 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21323323 is a deficient number, since it is larger than the sum of its proper divisors (4988357).

21323323 is a wasteful number, since it uses less digits than its factorization.

21323323 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4626.

The product of its digits is 648, while the sum is 19.

The square root of 21323323 is about 4617.7183759948. The cubic root of 21323323 is about 277.3011230941.

Adding to 21323323 its reverse (32332312), we get a palindrome (53655635).

The spelling of 21323323 in words is "twenty-one million, three hundred twenty-three thousand, three hundred twenty-three".