21041803 has 4 divisors (see below), whose sum is σ = 21956688. Its totient is φ = 20126920.

The previous prime is 21041771. The next prime is 21041807. The reversal of 21041803 is 30814012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21041803 - 2⁵ = 21041771 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21041807) 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, 457408 + ... + 457453.

It is an arithmetic number, because the mean of its divisors is an integer number (5489172).

Almost surely, 2^21041803 is an apocalyptic number.

21041803 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21041803 is a deficient number, since it is larger than the sum of its proper divisors (914885).

21041803 is an equidigital number, since it uses as much as digits as its factorization.

21041803 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 914884.

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 21041803 is about 4587.1345086012. The cubic root of 21041803 is about 276.0753618682.

Adding to 21041803 its reverse (30814012), we get a palindrome (51855815).

The spelling of 21041803 in words is "twenty-one million, forty-one thousand, eight hundred three".