133159981 has 2 divisors, whose sum is σ = 133159982. Its totient is φ = 133159980.

The previous prime is 133159933. The next prime is 133159993. The reversal of 133159981 is 189951331.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 67404100 + 65755881 = 8210^2 + 8109^2 .

It is an emirp because it is prime and its reverse (189951331) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 133159981 - 2⁷ = 133159853 is a prime.

It is a super-2 number, since 2×133159981² = 35463161079840722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (133156981) 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, 66579990 + 66579991.

It is an arithmetic number, because the mean of its divisors is an integer number (66579991).

Almost surely, 2^133159981 is an apocalyptic number.

It is an amenable number.

133159981 is a deficient number, since it is larger than the sum of its proper divisors (1).

133159981 is an equidigital number, since it uses as much as digits as its factorization.

133159981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 29160, while the sum is 40.

The square root of 133159981 is about 11539.4965661419. The cubic root of 133159981 is about 510.6514563611.

The spelling of 133159981 in words is "one hundred thirty-three million, one hundred fifty-nine thousand, nine hundred eighty-one".