171010991 has 2 divisors, whose sum is σ = 171010992. Its totient is φ = 171010990.

The previous prime is 171010981. The next prime is 171011021. The reversal of 171010991 is 199010171.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 171010991 - 2¹⁸ = 170748847 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (171010901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85505495 + 85505496.

It is an arithmetic number, because the mean of its divisors is an integer number (85505496).

Almost surely, 2^171010991 is an apocalyptic number.

171010991 is a deficient number, since it is larger than the sum of its proper divisors (1).

171010991 is an equidigital number, since it uses as much as digits as its factorization.

171010991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 567, while the sum is 29.

The square root of 171010991 is about 13077.1170752578. The cubic root of 171010991 is about 555.0618019537.

The spelling of 171010991 in words is "one hundred seventy-one million, ten thousand, nine hundred ninety-one".