21312330331 has 2 divisors, whose sum is σ = 21312330332. Its totient is φ = 21312330330.

The previous prime is 21312330329. The next prime is 21312330349. The reversal of 21312330331 is 13303321312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21312330331 - 2¹ = 21312330329 is a prime.

It is a super-2 number, since 2×21312330331² (a number of 21 digits) contains 22 as substring.

Together with 21312330329, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21312330371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10656165165 + 10656165166.

It is an arithmetic number, because the mean of its divisors is an integer number (10656165166).

Almost surely, 2^21312330331 is an apocalyptic number.

21312330331 is a deficient number, since it is larger than the sum of its proper divisors (1).

21312330331 is an equidigital number, since it uses as much as digits as its factorization.

21312330331 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 972, while the sum is 22.

Adding to 21312330331 its reverse (13303321312), we get a palindrome (34615651643).

The spelling of 21312330331 in words is "twenty-one billion, three hundred twelve million, three hundred thirty thousand, three hundred thirty-one".