21444533 has 8 divisors (see below), whose sum is σ = 24411456. Its totient is φ = 18647200.

The previous prime is 21444499. The next prime is 21444541. The reversal of 21444533 is 33544412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21444533 - 2¹⁰ = 21443509 is a prime.

It is a Duffinian number.

It is a zygodrome in base 3.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21444583) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42128 + ... + 42633.

It is an arithmetic number, because the mean of its divisors is an integer number (3051432).

Almost surely, 2^21444533 is an apocalyptic number.

21444533 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21444533 is a deficient number, since it is larger than the sum of its proper divisors (2966923).

21444533 is a wasteful number, since it uses less digits than its factorization.

21444533 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84795.

The product of its digits is 5760, while the sum is 26.

The square root of 21444533 is about 4630.8242246926. The cubic root of 21444533 is about 277.8255595256.

Adding to 21444533 its reverse (33544412), we get a palindrome (54988945).

The spelling of 21444533 in words is "twenty-one million, four hundred forty-four thousand, five hundred thirty-three".