21313302123 has 4 divisors (see below), whose sum is σ = 28417736168. Its totient is φ = 14208868080.

The previous prime is 21313302077. The next prime is 21313302149. The reversal of 21313302123 is 32120331312.

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

It is not a de Polignac number, because 21313302123 - 2¹⁷ = 21313171051 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 21313302123.

It is not an unprimeable number, because it can be changed into a prime (21313302163) 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, 3552217018 + ... + 3552217023.

It is an arithmetic number, because the mean of its divisors is an integer number (7104434042).

Almost surely, 2^21313302123 is an apocalyptic number.

21313302123 is a deficient number, since it is larger than the sum of its proper divisors (7104434045).

21313302123 is an equidigital number, since it uses as much as digits as its factorization.

21313302123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7104434044.

The product of its (nonzero) digits is 648, while the sum is 21.

Adding to 21313302123 its reverse (32120331312), we get a palindrome (53433633435).

The spelling of 21313302123 in words is "twenty-one billion, three hundred thirteen million, three hundred two thousand, one hundred twenty-three".