21203112103 has 4 divisors (see below), whose sum is σ = 21413044008. Its totient is φ = 20993180200.

The previous prime is 21203112101. The next prime is 21203112127. The reversal of 21203112103 is 30121130212.

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 21203112103 - 2¹ = 21203112101 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 (21203112101) 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, 104965801 + ... + 104966002.

It is an arithmetic number, because the mean of its divisors is an integer number (5353261002).

Almost surely, 2^21203112103 is an apocalyptic number.

21203112103 is a deficient number, since it is larger than the sum of its proper divisors (209931905).

21203112103 is a wasteful number, since it uses less digits than its factorization.

21203112103 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209931904.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21203112103 its reverse (30121130212), we get a palindrome (51324242315).

The spelling of 21203112103 in words is "twenty-one billion, two hundred three million, one hundred twelve thousand, one hundred three".