21304103 has 4 divisors (see below), whose sum is σ = 21313368. Its totient is φ = 21294840.

The previous prime is 21304097. The next prime is 21304109. The reversal of 21304103 is 30140312.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is an interprime number because it is at equal distance from previous prime (21304097) and next prime (21304109).

It is a cyclic number.

It is not a de Polignac number, because 21304103 - 2⁸ = 21303847 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 (21304109) 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, 1733 + ... + 6753.

It is an arithmetic number, because the mean of its divisors is an integer number (5328342).

Almost surely, 2^21304103 is an apocalyptic number.

21304103 is a deficient number, since it is larger than the sum of its proper divisors (9265).

21304103 is an equidigital number, since it uses as much as digits as its factorization.

21304103 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9264.

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 21304103 is about 4615.6367924697. The cubic root of 21304103 is about 277.2177819607.

Adding to 21304103 its reverse (30140312), we get a palindrome (51444415).

The spelling of 21304103 in words is "twenty-one million, three hundred four thousand, one hundred three".