21233203309 has 2 divisors, whose sum is σ = 21233203310. Its totient is φ = 21233203308.

The previous prime is 21233203297. The next prime is 21233203331. The reversal of 21233203309 is 90330233212.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18161605225 + 3071598084 = 134765^2 + 55422^2 .

It is a cyclic number.

It is not a de Polignac number, because 21233203309 - 2¹¹ = 21233201261 is a prime.

It is a super-2 number, since 2×21233203309² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21233203709) 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, 10616601654 + 10616601655.

It is an arithmetic number, because the mean of its divisors is an integer number (10616601655).

Almost surely, 2^21233203309 is an apocalyptic number.

It is an amenable number.

21233203309 is a deficient number, since it is larger than the sum of its proper divisors (1).

21233203309 is an equidigital number, since it uses as much as digits as its factorization.

21233203309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5832, while the sum is 28.

The spelling of 21233203309 in words is "twenty-one billion, two hundred thirty-three million, two hundred three thousand, three hundred nine".