21324043 has 4 divisors (see below), whose sum is σ = 22964368. Its totient is φ = 19683720.

The previous prime is 21324031. The next prime is 21324047. The reversal of 21324043 is 34042312.

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

It is a cyclic number.

It is not a de Polignac number, because 21324043 - 2⁵ = 21324011 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 21324043.

It is not an unprimeable number, because it can be changed into a prime (21324047) 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, 820143 + ... + 820168.

It is an arithmetic number, because the mean of its divisors is an integer number (5741092).

Almost surely, 2^21324043 is an apocalyptic number.

21324043 is a deficient number, since it is larger than the sum of its proper divisors (1640325).

21324043 is a wasteful number, since it uses less digits than its factorization.

21324043 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1640324.

The product of its (nonzero) digits is 576, while the sum is 19.

The square root of 21324043 is about 4617.7963359161. The cubic root of 21324043 is about 277.3042441612.

Adding to 21324043 its reverse (34042312), we get a palindrome (55366355).

The spelling of 21324043 in words is "twenty-one million, three hundred twenty-four thousand, forty-three".