Adding to 21313220311303 its reverse (30311302231312), we get a palindrome (51624522542615).
It is a semiprime because it is the product of two primes.
It is a de Polignac number, because none of the positive numbers 2k-21313220311303 is a prime.
It is a Duffinian number.
It is a congruent number.
Almost surely, 221313220311303 is an apocalyptic number.
21313220311303 is a wasteful number, since it uses less digits than its factorization.
21313220311303 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 1121748437456.
The spelling of 21313220311303 in words is "twenty-one trillion, three hundred thirteen billion, two hundred twenty million, three hundred eleven thousand, three hundred three".