133663681 has 2 divisors, whose sum is σ = 133663682. Its totient is φ = 133663680.

The previous prime is 133663643. The next prime is 133663687. The reversal of 133663681 is 186366331.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 123321025 + 10342656 = 11105^2 + 3216^2 .

It is a cyclic number.

It is not a de Polignac number, because 133663681 - 2²¹ = 131566529 is a prime.

It is a super-2 number, since 2×133663681² = 35731959236939522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 133663681.

It is not a weakly prime, because it can be changed into another prime (133663687) 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, 66831840 + 66831841.

It is an arithmetic number, because the mean of its divisors is an integer number (66831841).

Almost surely, 2^133663681 is an apocalyptic number.

It is an amenable number.

133663681 is a deficient number, since it is larger than the sum of its proper divisors (1).

133663681 is an equidigital number, since it uses as much as digits as its factorization.

133663681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 46656, while the sum is 37.

The square root of 133663681 is about 11561.3010081046. The cubic root of 133663681 is about 511.2945211835.

The spelling of 133663681 in words is "one hundred thirty-three million, six hundred sixty-three thousand, six hundred eighty-one".