21231344231 has 2 divisors, whose sum is σ = 21231344232. Its totient is φ = 21231344230.

The previous prime is 21231344227. The next prime is 21231344261. The reversal of 21231344231 is 13244313212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21231344231 - 2² = 21231344227 is a prime.

It is a super-2 number, since 2×21231344231² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21231344231.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21231344221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615672115 + 10615672116.

It is an arithmetic number, because the mean of its divisors is an integer number (10615672116).

Almost surely, 2^21231344231 is an apocalyptic number.

21231344231 is a deficient number, since it is larger than the sum of its proper divisors (1).

21231344231 is an equidigital number, since it uses as much as digits as its factorization.

21231344231 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3456, while the sum is 26.

Adding to 21231344231 its reverse (13244313212), we get a palindrome (34475657443).

The spelling of 21231344231 in words is "twenty-one billion, two hundred thirty-one million, three hundred forty-four thousand, two hundred thirty-one".