171668213 has 4 divisors (see below), whose sum is σ = 174482508. Its totient is φ = 168853920.

The previous prime is 171668209. The next prime is 171668243. The reversal of 171668213 is 312866171.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 312866171 = 23 ⋅13602877.

It can be written as a sum of positive squares in 2 ways, for example, as 82119844 + 89548369 = 9062^2 + 9463^2 .

It is a cyclic number.

It is not a de Polignac number, because 171668213 - 2² = 171668209 is a prime.

It is a super-2 number, since 2×171668213² = 58939950709226738, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (171668243) 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 3 ways as a sum of consecutive naturals, for example, 1407056 + ... + 1407177.

It is an arithmetic number, because the mean of its divisors is an integer number (43620627).

Almost surely, 2^171668213 is an apocalyptic number.

It is an amenable number.

171668213 is a deficient number, since it is larger than the sum of its proper divisors (2814295).

171668213 is an equidigital number, since it uses as much as digits as its factorization.

171668213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2814294.

The product of its digits is 12096, while the sum is 35.

The square root of 171668213 is about 13102.2216818370. The cubic root of 171668213 is about 555.7719561069.

The spelling of 171668213 in words is "one hundred seventy-one million, six hundred sixty-eight thousand, two hundred thirteen".