21826664669 has 2 divisors, whose sum is σ = 21826664670. Its totient is φ = 21826664668.

The previous prime is 21826664659. The next prime is 21826664677. The reversal of 21826664669 is 96646662812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21210135769 + 616528900 = 145637^2 + 24830^2 .

It is a cyclic number.

It is not a de Polignac number, because 21826664669 - 2⁴ = 21826664653 is a prime.

It is a super-3 number, since 3×21826664669³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21826664609) 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, 10913332334 + 10913332335.

It is an arithmetic number, because the mean of its divisors is an integer number (10913332335).

Almost surely, 2^21826664669 is an apocalyptic number.

It is an amenable number.

21826664669 is a deficient number, since it is larger than the sum of its proper divisors (1).

21826664669 is an equidigital number, since it uses as much as digits as its factorization.

21826664669 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8957952, while the sum is 56.

The spelling of 21826664669 in words is "twenty-one billion, eight hundred twenty-six million, six hundred sixty-four thousand, six hundred sixty-nine".