21323105 has 4 divisors (see below), whose sum is σ = 25587732. Its totient is φ = 17058480.

The previous prime is 21323089. The next prime is 21323129. The reversal of 21323105 is 50132312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15936064 + 5387041 = 3992^2 + 2321^2 .

It is not a de Polignac number, because 21323105 - 2⁴ = 21323089 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2132306 + ... + 2132315.

It is an arithmetic number, because the mean of its divisors is an integer number (6396933).

Almost surely, 2^21323105 is an apocalyptic number.

It is an amenable number.

21323105 is a deficient number, since it is larger than the sum of its proper divisors (4264627).

21323105 is an equidigital number, since it uses as much as digits as its factorization.

21323105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4264626.

The product of its (nonzero) digits is 180, while the sum is 17.

The square root of 21323105 is about 4617.6947712035. The cubic root of 21323105 is about 277.3001780906.

Adding to 21323105 its reverse (50132312), we get a palindrome (71455417).

The spelling of 21323105 in words is "twenty-one million, three hundred twenty-three thousand, one hundred five".