21089003 has 16 divisors (see below), whose sum is σ = 23704800. Its totient is φ = 18738720.

The previous prime is 21088997. The next prime is 21089009. The reversal of 21089003 is 30098012.

It is an interprime number because it is at equal distance from previous prime (21088997) and next prime (21089009).

It is not a de Polignac number, because 21089003 - 2⁸ = 21088747 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21089003.

It is not an unprimeable number, because it can be changed into a prime (21089009) 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 15 ways as a sum of consecutive naturals, for example, 63548 + ... + 63878.

It is an arithmetic number, because the mean of its divisors is an integer number (1481550).

Almost surely, 2^21089003 is an apocalyptic number.

21089003 is a deficient number, since it is larger than the sum of its proper divisors (2615797).

21089003 is an equidigital number, since it uses as much as digits as its factorization.

21089003 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 399 (or 373 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 21089003 is about 4592.2764507377. The cubic root of 21089003 is about 276.2816342089.

Subtracting 21089003 from its reverse (30098012), we obtain a palindrome (9009009).

It can be divided in two parts, 2108 and 9003, that added together give a palindrome (11111).

The spelling of 21089003 in words is "twenty-one million, eighty-nine thousand, three".