217906133 has 4 divisors (see below), whose sum is σ = 217940268. Its totient is φ = 217872000.

The previous prime is 217906121. The next prime is 217906141. The reversal of 217906133 is 331609712.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 43850884 + 174055249 = 6622^2 + 13193^2 .

It is a cyclic number.

It is not a de Polignac number, because 217906133 - 2¹² = 217902037 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 217906133.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217906433) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4316 + ... + 21317.

It is an arithmetic number, because the mean of its divisors is an integer number (54485067).

Almost surely, 2^217906133 is an apocalyptic number.

It is an amenable number.

217906133 is a deficient number, since it is larger than the sum of its proper divisors (34135).

217906133 is an equidigital number, since it uses as much as digits as its factorization.

217906133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34134.

The product of its (nonzero) digits is 6804, while the sum is 32.

The square root of 217906133 is about 14761.6439802618. The cubic root of 217906133 is about 601.7597715902.

The spelling of 217906133 in words is "two hundred seventeen million, nine hundred six thousand, one hundred thirty-three".