133518221 has 8 divisors (see below), whose sum is σ = 141993720. Its totient is φ = 125111808.

The previous prime is 133518191. The next prime is 133518223. The reversal of 133518221 is 122815331.

It can be written as a sum of positive squares in 4 ways, for example, as 103815721 + 29702500 = 10189^2 + 5450^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 133518221 - 2⁶ = 133518157 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133518223) 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 in 7 ways as a sum of consecutive naturals, for example, 13256 + ... + 21041.

It is an arithmetic number, because the mean of its divisors is an integer number (17749215).

Almost surely, 2^133518221 is an apocalyptic number.

It is an amenable number.

133518221 is a deficient number, since it is larger than the sum of its proper divisors (8475499).

133518221 is a wasteful number, since it uses less digits than its factorization.

133518221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34543.

The product of its digits is 1440, while the sum is 26.

The square root of 133518221 is about 11555.0084811739. The cubic root of 133518221 is about 511.1089811383.

The spelling of 133518221 in words is "one hundred thirty-three million, five hundred eighteen thousand, two hundred twenty-one".