21240333 has 16 divisors (see below), whose sum is σ = 32063040. Its totient is φ = 13892112.

The previous prime is 21240313. The next prime is 21240377. The reversal of 21240333 is 33304212.

It is not a de Polignac number, because 21240333 - 2¹⁷ = 21109261 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21240313) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5991 + ... + 8852.

It is an arithmetic number, because the mean of its divisors is an integer number (2003940).

Almost surely, 2^21240333 is an apocalyptic number.

It is an amenable number.

21240333 is a deficient number, since it is larger than the sum of its proper divisors (10822707).

21240333 is a wasteful number, since it uses less digits than its factorization.

21240333 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14905 (or 14899 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 18.

The square root of 21240333 is about 4608.7235760024. The cubic root of 21240333 is about 276.9409049954.

Adding to 21240333 its reverse (33304212), we get a palindrome (54544545).

The spelling of 21240333 in words is "twenty-one million, two hundred forty thousand, three hundred thirty-three".