21203111023 has 4 divisors (see below), whose sum is σ = 21210587640. Its totient is φ = 21195634408.

The previous prime is 21203111003. The next prime is 21203111029. The reversal of 21203111023 is 32011130212.

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 21203111023 - 2³³ = 12613176431 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21203110988 and 21203111006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21203111029) 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, 3734053 + ... + 3739726.

It is an arithmetic number, because the mean of its divisors is an integer number (5302646910).

Almost surely, 2^21203111023 is an apocalyptic number.

21203111023 is a deficient number, since it is larger than the sum of its proper divisors (7476617).

21203111023 is an equidigital number, since it uses as much as digits as its factorization.

21203111023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7476616.

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

Adding to 21203111023 its reverse (32011130212), we get a palindrome (53214241235).

The spelling of 21203111023 in words is "twenty-one billion, two hundred three million, one hundred eleven thousand, twenty-three".