21312313333 has 2 divisors, whose sum is σ = 21312313334. Its totient is φ = 21312313332.

The previous prime is 21312313271. The next prime is 21312313339. The reversal of 21312313333 is 33331321312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15241877764 + 6070435569 = 123458^2 + 77913^2 .

It is a cyclic number.

It is not a de Polignac number, because 21312313333 - 2²⁹ = 20775442421 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21312313298 and 21312313307.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21312313339) 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, 10656156666 + 10656156667.

It is an arithmetic number, because the mean of its divisors is an integer number (10656156667).

Almost surely, 2^21312313333 is an apocalyptic number.

It is an amenable number.

21312313333 is a deficient number, since it is larger than the sum of its proper divisors (1).

21312313333 is an equidigital number, since it uses as much as digits as its factorization.

21312313333 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2916, while the sum is 25.

Adding to 21312313333 its reverse (33331321312), we get a palindrome (54643634645).

The spelling of 21312313333 in words is "twenty-one billion, three hundred twelve million, three hundred thirteen thousand, three hundred thirty-three".