21101243223 has 4 divisors (see below), whose sum is σ = 28134990968. Its totient is φ = 14067495480.

The previous prime is 21101243213. The next prime is 21101243263. The reversal of 21101243223 is 32234210112.

It is a semiprime because it is the product of two primes.

It is a de Polignac number, because none of the positive numbers 2^k-21101243223 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21101243223.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101243203) 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, 3516873868 + ... + 3516873873.

It is an arithmetic number, because the mean of its divisors is an integer number (7033747742).

Almost surely, 2^21101243223 is an apocalyptic number.

21101243223 is a deficient number, since it is larger than the sum of its proper divisors (7033747745).

21101243223 is an equidigital number, since it uses as much as digits as its factorization.

21101243223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7033747744.

The product of its (nonzero) digits is 576, while the sum is 21.

Adding to 21101243223 its reverse (32234210112), we get a palindrome (53335453335).

The spelling of 21101243223 in words is "twenty-one billion, one hundred one million, two hundred forty-three thousand, two hundred twenty-three".