21231112361 has 2 divisors, whose sum is σ = 21231112362. Its totient is φ = 21231112360.

The previous prime is 21231112249. The next prime is 21231112379. The reversal of 21231112361 is 16321113212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19661367961 + 1569744400 = 140219^2 + 39620^2 .

It is a cyclic number.

It is not a de Polignac number, because 21231112361 - 2¹⁸ = 21230850217 is a prime.

It is a super-3 number, since 3×21231112361³ (a number of 32 digits) contains 333 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21231112391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615556180 + 10615556181.

It is an arithmetic number, because the mean of its divisors is an integer number (10615556181).

Almost surely, 2^21231112361 is an apocalyptic number.

It is an amenable number.

21231112361 is a deficient number, since it is larger than the sum of its proper divisors (1).

21231112361 is an equidigital number, since it uses as much as digits as its factorization.

21231112361 is an evil number, because the sum of its binary digits is even.

The product of its digits is 432, while the sum is 23.

Adding to 21231112361 its reverse (16321113212), we get a palindrome (37552225573).

The spelling of 21231112361 in words is "twenty-one billion, two hundred thirty-one million, one hundred twelve thousand, three hundred sixty-one".