21311123203 has 4 divisors (see below), whose sum is σ = 21335150160. Its totient is φ = 21287096248.

The previous prime is 21311123189. The next prime is 21311123219. The reversal of 21311123203 is 30232111312.

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 21311123203 - 2⁹ = 21311122691 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21311123233) 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, 12012148 + ... + 12013921.

It is an arithmetic number, because the mean of its divisors is an integer number (5333787540).

Almost surely, 2^21311123203 is an apocalyptic number.

21311123203 is a deficient number, since it is larger than the sum of its proper divisors (24026957).

21311123203 is an equidigital number, since it uses as much as digits as its factorization.

21311123203 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24026956.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 21311123203 its reverse (30232111312), we get a palindrome (51543234515).

The spelling of 21311123203 in words is "twenty-one billion, three hundred eleven million, one hundred twenty-three thousand, two hundred three".