21333833 has 4 divisors (see below), whose sum is σ = 21354180. Its totient is φ = 21313488.

The previous prime is 21333779. The next prime is 21333839. The reversal of 21333833 is 33833312.

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 1236544 + 20097289 = 1112^2 + 4483^2 .

It is a cyclic number.

It is not a de Polignac number, because 21333833 - 2⁶ = 21333769 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21333839) 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, 8510 + ... + 10727.

It is an arithmetic number, because the mean of its divisors is an integer number (5338545).

Almost surely, 2^21333833 is an apocalyptic number.

It is an amenable number.

21333833 is a deficient number, since it is larger than the sum of its proper divisors (20347).

21333833 is a wasteful number, since it uses less digits than its factorization.

21333833 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20346.

The product of its digits is 3888, while the sum is 26.

The square root of 21333833 is about 4618.8562437036. The cubic root of 21333833 is about 277.3466750328.

The spelling of 21333833 in words is "twenty-one million, three hundred thirty-three thousand, eight hundred thirty-three".