21804733 has 4 divisors (see below), whose sum is σ = 22049820. Its totient is φ = 21559648.

The previous prime is 21804719. The next prime is 21804737. The reversal of 21804733 is 33740812.

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 + 7387524 = 3797^2 + 2718^2 .

It is a cyclic number.

It is not a de Polignac number, because 21804733 - 2⁵ = 21804701 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21804737) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 122410 + ... + 122587.

It is an arithmetic number, because the mean of its divisors is an integer number (5512455).

Almost surely, 2^21804733 is an apocalyptic number.

It is an amenable number.

21804733 is a deficient number, since it is larger than the sum of its proper divisors (245087).

21804733 is an equidigital number, since it uses as much as digits as its factorization.

21804733 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 245086.

The product of its (nonzero) digits is 4032, while the sum is 28.

The square root of 21804733 is about 4669.5538330766. The cubic root of 21804733 is about 279.3724593923.

The spelling of 21804733 in words is "twenty-one million, eight hundred four thousand, seven hundred thirty-three".