21166066133 has 2 divisors, whose sum is σ = 21166066134. Its totient is φ = 21166066132.

The previous prime is 21166066079. The next prime is 21166066211. The reversal of 21166066133 is 33166066112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16210891684 + 4955174449 = 127322^2 + 70393^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21166066133 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21166066093 and 21166066102.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11166066133) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10583033066 + 10583033067.

It is an arithmetic number, because the mean of its divisors is an integer number (10583033067).

Almost surely, 2^21166066133 is an apocalyptic number.

It is an amenable number.

21166066133 is a deficient number, since it is larger than the sum of its proper divisors (1).

21166066133 is an equidigital number, since it uses as much as digits as its factorization.

21166066133 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23328, while the sum is 35.

The spelling of 21166066133 in words is "twenty-one billion, one hundred sixty-six million, sixty-six thousand, one hundred thirty-three".