21244323 has 4 divisors (see below), whose sum is σ = 28325768. Its totient is φ = 14162880.

The previous prime is 21244309. The next prime is 21244367. The reversal of 21244323 is 32344212.

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

It is not a de Polignac number, because 21244323 - 2⁵ = 21244291 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 21244323.

It is not an unprimeable number, because it can be changed into a prime (21244303) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3540718 + ... + 3540723.

It is an arithmetic number, because the mean of its divisors is an integer number (7081442).

Almost surely, 2^21244323 is an apocalyptic number.

21244323 is a deficient number, since it is larger than the sum of its proper divisors (7081445).

21244323 is an equidigital number, since it uses as much as digits as its factorization.

21244323 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7081444.

The product of its digits is 1152, while the sum is 21.

The square root of 21244323 is about 4609.1564304111. The cubic root of 21244323 is about 276.9582450410.

Adding to 21244323 its reverse (32344212), we get a palindrome (53588535).

The spelling of 21244323 in words is "twenty-one million, two hundred forty-four thousand, three hundred twenty-three".