21344323181 has 2 divisors, whose sum is σ = 21344323182. Its totient is φ = 21344323180.

The previous prime is 21344323177. The next prime is 21344323207. The reversal of 21344323181 is 18132344312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14050309156 + 7294014025 = 118534^2 + 85405^2 .

It is a cyclic number.

It is not a de Polignac number, because 21344323181 - 2² = 21344323177 is a prime.

It is a super-2 number, since 2×21344323181² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21344323381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10672161590 + 10672161591.

It is an arithmetic number, because the mean of its divisors is an integer number (10672161591).

Almost surely, 2^21344323181 is an apocalyptic number.

It is an amenable number.

21344323181 is a deficient number, since it is larger than the sum of its proper divisors (1).

21344323181 is an equidigital number, since it uses as much as digits as its factorization.

21344323181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13824, while the sum is 32.

Adding to 21344323181 its reverse (18132344312), we get a palindrome (39476667493).

The spelling of 21344323181 in words is "twenty-one billion, three hundred forty-four million, three hundred twenty-three thousand, one hundred eighty-one".