133236221 has 2 divisors, whose sum is σ = 133236222. Its totient is φ = 133236220.

The previous prime is 133236197. The next prime is 133236239. The reversal of 133236221 is 122632331.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 121771225 + 11464996 = 11035^2 + 3386^2 .

It is an emirp because it is prime and its reverse (122632331) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-133236221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (133236241) 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, 66618110 + 66618111.

It is an arithmetic number, because the mean of its divisors is an integer number (66618111).

Almost surely, 2^133236221 is an apocalyptic number.

It is an amenable number.

133236221 is a deficient number, since it is larger than the sum of its proper divisors (1).

133236221 is an equidigital number, since it uses as much as digits as its factorization.

133236221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1296, while the sum is 23.

The square root of 133236221 is about 11542.7995304432. The cubic root of 133236221 is about 510.7488946430.

Adding to 133236221 its reverse (122632331), we get a palindrome (255868552).

The spelling of 133236221 in words is "one hundred thirty-three million, two hundred thirty-six thousand, two hundred twenty-one".