171323981 has 2 divisors, whose sum is σ = 171323982. Its totient is φ = 171323980.

The previous prime is 171323951. The next prime is 171323983. The reversal of 171323981 is 189323171.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 167055625 + 4268356 = 12925^2 + 2066^2 .

It is an emirp because it is prime and its reverse (189323171) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-171323981 is a prime.

It is a super-2 number, since 2×171323981² = 58703812931376722, which contains 22 as substring.

Together with 171323983, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (171323983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85661990 + 85661991.

It is an arithmetic number, because the mean of its divisors is an integer number (85661991).

Almost surely, 2^171323981 is an apocalyptic number.

It is an amenable number.

171323981 is a deficient number, since it is larger than the sum of its proper divisors (1).

171323981 is an equidigital number, since it uses as much as digits as its factorization.

171323981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9072, while the sum is 35.

The square root of 171323981 is about 13089.0786917949. The cubic root of 171323981 is about 555.4002264256.

The spelling of 171323981 in words is "one hundred seventy-one million, three hundred twenty-three thousand, nine hundred eighty-one".