21012317233 has 2 divisors, whose sum is σ = 21012317234. Its totient is φ = 21012317232.

The previous prime is 21012317167. The next prime is 21012317239. The reversal of 21012317233 is 33271321012.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17506729969 + 3505587264 = 132313^2 + 59208^2 .

It is a cyclic number.

It is not a de Polignac number, because 21012317233 - 2¹⁷ = 21012186161 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21012317198 and 21012317207.

It is not a weakly prime, because it can be changed into another prime (21012317239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506158616 + 10506158617.

It is an arithmetic number, because the mean of its divisors is an integer number (10506158617).

Almost surely, 2^21012317233 is an apocalyptic number.

It is an amenable number.

21012317233 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012317233 is an equidigital number, since it uses as much as digits as its factorization.

21012317233 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1512, while the sum is 25.

Adding to 21012317233 its reverse (33271321012), we get a palindrome (54283638245).

The spelling of 21012317233 in words is "twenty-one billion, twelve million, three hundred seventeen thousand, two hundred thirty-three".