171353316221 has 4 divisors (see below), whose sum is σ = 172604070492. Its totient is φ = 170102561952.

The previous prime is 171353316193. The next prime is 171353316283. The reversal of 171353316221 is 122613353171.

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 112636756996 + 58716559225 = 335614^2 + 242315^2 .

It is a cyclic number.

It is not a de Polignac number, because 171353316221 - 2¹⁸ = 171353054077 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 (171353316521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 625376930 + ... + 625377203.

It is an arithmetic number, because the mean of its divisors is an integer number (43151017623).

Almost surely, 2^171353316221 is an apocalyptic number.

It is an amenable number.

171353316221 is a deficient number, since it is larger than the sum of its proper divisors (1250754271).

171353316221 is a wasteful number, since it uses less digits than its factorization.

171353316221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1250754270.

The product of its digits is 22680, while the sum is 35.

Adding to 171353316221 its reverse (122613353171), we get a palindrome (293966669392).

The spelling of 171353316221 in words is "one hundred seventy-one billion, three hundred fifty-three million, three hundred sixteen thousand, two hundred twenty-one".