666636133 has 2 divisors, whose sum is σ = 666636134. Its totient is φ = 666636132.

The previous prime is 666636127. The next prime is 666636149. The reversal of 666636133 is 331636666.

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., 448719489 + 217916644 = 21183^2 + 14762^2 .

It is a cyclic number.

It is not a de Polignac number, because 666636133 - 2⁹ = 666635621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666616133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333318066 + 333318067.

It is an arithmetic number, because the mean of its divisors is an integer number (333318067).

Almost surely, 2^666636133 is an apocalyptic number.

It is an amenable number.

666636133 is a deficient number, since it is larger than the sum of its proper divisors (1).

666636133 is an equidigital number, since it uses as much as digits as its factorization.

666636133 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 209952, while the sum is 40.

The square root of 666636133 is about 25819.2976860332. The cubic root of 666636133 is about 873.5671277253.

The spelling of 666636133 in words is "six hundred sixty-six million, six hundred thirty-six thousand, one hundred thirty-three".