21324133 has 4 divisors (see below), whose sum is σ = 21563820. Its totient is φ = 21084448.

The previous prime is 21324119. The next prime is 21324139. The reversal of 21324133 is 33142312.

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 2505889 + 18818244 = 1583^2 + 4338^2 .

It is a cyclic number.

It is not a de Polignac number, because 21324133 - 2⁵ = 21324101 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 21324133.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21324139) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 119710 + ... + 119887.

It is an arithmetic number, because the mean of its divisors is an integer number (5390955).

Almost surely, 2^21324133 is an apocalyptic number.

It is an amenable number.

21324133 is a deficient number, since it is larger than the sum of its proper divisors (239687).

21324133 is an equidigital number, since it uses as much as digits as its factorization.

21324133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 239686.

The product of its digits is 432, while the sum is 19.

The square root of 21324133 is about 4617.8060808137. The cubic root of 21324133 is about 277.3046342896.

Adding to 21324133 its reverse (33142312), we get a palindrome (54466445).

The spelling of 21324133 in words is "twenty-one million, three hundred twenty-four thousand, one hundred thirty-three".