21403103 has 4 divisors (see below), whose sum is σ = 21603240. Its totient is φ = 21202968.

The previous prime is 21403097. The next prime is 21403111. The reversal of 21403103 is 30130412.

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 21403103 - 2¹⁰ = 21402079 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 (21403303) 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, 99908 + ... + 100121.

It is an arithmetic number, because the mean of its divisors is an integer number (5400810).

Almost surely, 2^21403103 is an apocalyptic number.

21403103 is a deficient number, since it is larger than the sum of its proper divisors (200137).

21403103 is a wasteful number, since it uses less digits than its factorization.

21403103 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 200136.

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

The square root of 21403103 is about 4626.3487763030. The cubic root of 21403103 is about 277.6465281397.

Adding to 21403103 its reverse (30130412), we get a palindrome (51533515).

The spelling of 21403103 in words is "twenty-one million, four hundred three thousand, one hundred three".