21301310123 has 4 divisors (see below), whose sum is σ = 21570947040. Its totient is φ = 21031673208.

The previous prime is 21301310119. The next prime is 21301310143. The reversal of 21301310123 is 32101310312.

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 21301310123 - 2² = 21301310119 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21301310143) 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, 134818340 + ... + 134818497.

It is an arithmetic number, because the mean of its divisors is an integer number (5392736760).

Almost surely, 2^21301310123 is an apocalyptic number.

21301310123 is a deficient number, since it is larger than the sum of its proper divisors (269636917).

21301310123 is an equidigital number, since it uses as much as digits as its factorization.

21301310123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 269636916.

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

Adding to 21301310123 its reverse (32101310312), we get a palindrome (53402620435).

The spelling of 21301310123 in words is "twenty-one billion, three hundred one million, three hundred ten thousand, one hundred twenty-three".