21323121331 has 2 divisors, whose sum is σ = 21323121332. Its totient is φ = 21323121330.

The previous prime is 21323121329. The next prime is 21323121361. The reversal of 21323121331 is 13312132312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21323121331 - 2¹ = 21323121329 is a prime.

It is a super-2 number, since 2×21323121331² (a number of 21 digits) contains 22 as substring.

Together with 21323121329, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21323121361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10661560665 + 10661560666.

It is an arithmetic number, because the mean of its divisors is an integer number (10661560666).

Almost surely, 2^21323121331 is an apocalyptic number.

21323121331 is a deficient number, since it is larger than the sum of its proper divisors (1).

21323121331 is an equidigital number, since it uses as much as digits as its factorization.

21323121331 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 648, while the sum is 22.

Adding to 21323121331 its reverse (13312132312), we get a palindrome (34635253643).

The spelling of 21323121331 in words is "twenty-one billion, three hundred twenty-three million, one hundred twenty-one thousand, three hundred thirty-one".