21011321212231 has 12 divisors (see below), whose sum is σ = 24467016901008. Its totient is φ = 17991079549632.

The previous prime is 21011321212153. The next prime is 21011321212289. The reversal of 21011321212231 is 13221212311012.

It is a happy number.

It is not a de Polignac number, because 21011321212231 - 2¹⁵ = 21011321179463 is a prime.

It is a super-2 number, since 2×21011321212231² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011321212031) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 221670546 + ... + 221765311.

It is an arithmetic number, because the mean of its divisors is an integer number (2038918075084).

Almost surely, 2^{21011321212231} is an apocalyptic number.

21011321212231 is a deficient number, since it is larger than the sum of its proper divisors (3455695688777).

21011321212231 is an equidigital number, since it uses as much as digits as its factorization.

21011321212231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 443436838 (or 443436831 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 22.

Adding to 21011321212231 its reverse (13221212311012), we get a palindrome (34232533523243).

The spelling of 21011321212231 in words is "twenty-one trillion, eleven billion, three hundred twenty-one million, two hundred twelve thousand, two hundred thirty-one".