21333473 has 12 divisors (see below), whose sum is σ = 25673940. Its totient is φ = 17654112.

The previous prime is 21333467. The next prime is 21333491. The reversal of 21333473 is 37433312.

It can be written as a sum of positive squares in 2 ways, for example, as 13454224 + 7879249 = 3668^2 + 2807^2 .

It is not a de Polignac number, because 21333473 - 2¹² = 21329377 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 (21333413) 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 11 ways as a sum of consecutive naturals, for example, 6086 + ... + 8927.

It is an arithmetic number, because the mean of its divisors is an integer number (2139495).

Almost surely, 2^21333473 is an apocalyptic number.

It is an amenable number.

21333473 is a deficient number, since it is larger than the sum of its proper divisors (4340467).

21333473 is a wasteful number, since it uses less digits than its factorization.

21333473 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15056 (or 15049 counting only the distinct ones).

The product of its digits is 4536, while the sum is 26.

The square root of 21333473 is about 4618.8172728524. The cubic root of 21333473 is about 277.3451149855.

Adding to 21333473 its reverse (37433312), we get a palindrome (58766785).

The spelling of 21333473 in words is "twenty-one million, three hundred thirty-three thousand, four hundred seventy-three".