21344633 has 4 divisors (see below), whose sum is σ = 21556068. Its totient is φ = 21133200.

The previous prime is 21344629. The next prime is 21344663. The reversal of 21344633 is 33644312.

It is a happy number.

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 14417209 + 6927424 = 3797^2 + 2632^2 .

It is a cyclic number.

It is not a de Polignac number, because 21344633 - 2² = 21344629 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21344623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 105566 + ... + 105767.

It is an arithmetic number, because the mean of its divisors is an integer number (5389017).

Almost surely, 2^21344633 is an apocalyptic number.

It is an amenable number.

21344633 is a deficient number, since it is larger than the sum of its proper divisors (211435).

21344633 is a wasteful number, since it uses less digits than its factorization.

21344633 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 211434.

The product of its digits is 5184, while the sum is 26.

The square root of 21344633 is about 4620.0252163814. The cubic root of 21344633 is about 277.3934682928.

Adding to 21344633 its reverse (33644312), we get a palindrome (54988945).

The spelling of 21344633 in words is "twenty-one million, three hundred forty-four thousand, six hundred thirty-three".