21321031103 has 4 divisors (see below), whose sum is σ = 21321450360. Its totient is φ = 21320611848.

The previous prime is 21321031063. The next prime is 21321031139. The reversal of 21321031103 is 30113012312.

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 21321031103 - 2¹⁰ = 21321030079 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 (21321031703) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 120800 + ... + 239237.

It is an arithmetic number, because the mean of its divisors is an integer number (5330362590).

Almost surely, 2^21321031103 is an apocalyptic number.

21321031103 is a deficient number, since it is larger than the sum of its proper divisors (419257).

21321031103 is an equidigital number, since it uses as much as digits as its factorization.

21321031103 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 419256.

The product of its (nonzero) digits is 108, while the sum is 17.

Adding to 21321031103 its reverse (30113012312), we get a palindrome (51434043415).

The spelling of 21321031103 in words is "twenty-one billion, three hundred twenty-one million, thirty-one thousand, one hundred three".