133506221 has 2 divisors, whose sum is σ = 133506222. Its totient is φ = 133506220.

The previous prime is 133506193. The next prime is 133506229. The reversal of 133506221 is 122605331.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 83521321 + 49984900 = 9139^2 + 7070^2 .

It is a cyclic number.

It is not a de Polignac number, because 133506221 - 2¹⁸ = 133244077 is a prime.

It is a super-2 number, since 2×133506221² = 35647822091401682, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (133506229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 66753110 + 66753111.

It is an arithmetic number, because the mean of its divisors is an integer number (66753111).

Almost surely, 2^133506221 is an apocalyptic number.

It is an amenable number.

133506221 is a deficient number, since it is larger than the sum of its proper divisors (1).

133506221 is an equidigital number, since it uses as much as digits as its factorization.

133506221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1080, while the sum is 23.

The square root of 133506221 is about 11554.4892141540. The cubic root of 133506221 is about 511.0936686427.

The spelling of 133506221 in words is "one hundred thirty-three million, five hundred six thousand, two hundred twenty-one".