21232003 has 4 divisors (see below), whose sum is σ = 22865248. Its totient is φ = 19598760.

The previous prime is 21231979. The next prime is 21232007. The reversal of 21232003 is 30023212.

It is a happy number.

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 21232003 - 2⁵ = 21231971 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13), and also a Moran number because the ratio is a prime number: 1633231 = 21232003 / (2 + 1 + 2 + 3 + 2 + 0 + 0 + 3).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21232007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 816603 + ... + 816628.

It is an arithmetic number, because the mean of its divisors is an integer number (5716312).

Almost surely, 2^21232003 is an apocalyptic number.

21232003 is a deficient number, since it is larger than the sum of its proper divisors (1633245).

21232003 is a wasteful number, since it uses less digits than its factorization.

21232003 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1633244.

The product of its (nonzero) digits is 72, while the sum is 13.

The square root of 21232003 is about 4607.8197664405. The cubic root of 21232003 is about 276.9046968471.

Adding to 21232003 its reverse (30023212), we get a palindrome (51255215).

The spelling of 21232003 in words is "twenty-one million, two hundred thirty-two thousand, three".