133516661 has 2 divisors, whose sum is σ = 133516662. Its totient is φ = 133516660.

The previous prime is 133516631. The next prime is 133516681. The reversal of 133516661 is 166615331.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 67338436 + 66178225 = 8206^2 + 8135^2 .

It is an emirp because it is prime and its reverse (166615331) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 133516661 - 2¹⁴ = 133500277 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (133516601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 66758330 + 66758331.

It is an arithmetic number, because the mean of its divisors is an integer number (66758331).

Almost surely, 2^133516661 is an apocalyptic number.

It is an amenable number.

133516661 is a deficient number, since it is larger than the sum of its proper divisors (1).

133516661 is an equidigital number, since it uses as much as digits as its factorization.

133516661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9720, while the sum is 32.

The square root of 133516661 is about 11554.9409777809. The cubic root of 133516661 is about 511.1069905657.

The spelling of 133516661 in words is "one hundred thirty-three million, five hundred sixteen thousand, six hundred sixty-one".