171663493 has 2 divisors, whose sum is σ = 171663494. Its totient is φ = 171663492.

The previous prime is 171663491. The next prime is 171663497. The reversal of 171663493 is 394366171.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 171662404 + 1089 = 13102^2 + 33^2 .

It is an emirp because it is prime and its reverse (394366171) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 171663493 - 2¹ = 171663491 is a prime.

It is a super-2 number, since 2×171663493² = 58936709657922098, which contains 22 as substring.

Together with 171663491, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (171663491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85831746 + 85831747.

It is an arithmetic number, because the mean of its divisors is an integer number (85831747).

Almost surely, 2^171663493 is an apocalyptic number.

It is an amenable number.

171663493 is a deficient number, since it is larger than the sum of its proper divisors (1).

171663493 is an equidigital number, since it uses as much as digits as its factorization.

171663493 is an evil number, because the sum of its binary digits is even.

The product of its digits is 81648, while the sum is 40.

The square root of 171663493 is about 13102.0415584748. The cubic root of 171663493 is about 555.7668624291.

The spelling of 171663493 in words is "one hundred seventy-one million, six hundred sixty-three thousand, four hundred ninety-three".