21112321361 has 2 divisors, whose sum is σ = 21112321362. Its totient is φ = 21112321360.

The previous prime is 21112321273. The next prime is 21112321379. The reversal of 21112321361 is 16312321112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21112090000 + 231361 = 145300^2 + 481^2 .

It is a cyclic number.

It is not a de Polignac number, because 21112321361 - 2¹⁸ = 21112059217 is a prime.

It is a super-2 number, since 2×21112321361² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21112321261) 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, 10556160680 + 10556160681.

It is an arithmetic number, because the mean of its divisors is an integer number (10556160681).

Almost surely, 2^21112321361 is an apocalyptic number.

It is an amenable number.

21112321361 is a deficient number, since it is larger than the sum of its proper divisors (1).

21112321361 is an equidigital number, since it uses as much as digits as its factorization.

21112321361 is an odious number, because the sum of its binary digits is odd.

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

Adding to 21112321361 its reverse (16312321112), we get a palindrome (37424642473).

The spelling of 21112321361 in words is "twenty-one billion, one hundred twelve million, three hundred twenty-one thousand, three hundred sixty-one".