21312330233 has 2 divisors, whose sum is σ = 21312330234. Its totient is φ = 21312330232.

The previous prime is 21312330209. The next prime is 21312330239. The reversal of 21312330233 is 33203321312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15119899369 + 6192430864 = 122963^2 + 78692^2 .

It is a cyclic number.

It is not a de Polignac number, because 21312330233 - 2⁸ = 21312329977 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21312330199 and 21312330208.

It is not a weakly prime, because it can be changed into another prime (21312330239) 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, 10656165116 + 10656165117.

It is an arithmetic number, because the mean of its divisors is an integer number (10656165117).

Almost surely, 2^21312330233 is an apocalyptic number.

It is an amenable number.

21312330233 is a deficient number, since it is larger than the sum of its proper divisors (1).

21312330233 is an equidigital number, since it uses as much as digits as its factorization.

21312330233 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1944, while the sum is 23.

Adding to 21312330233 its reverse (33203321312), we get a palindrome (54515651545).

The spelling of 21312330233 in words is "twenty-one billion, three hundred twelve million, three hundred thirty thousand, two hundred thirty-three".