171079991 has 4 divisors (see below), whose sum is σ = 171212592. Its totient is φ = 170947392.

The previous prime is 171079981. The next prime is 171080023. The reversal of 171079991 is 199970171.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 171079991 - 2¹⁰ = 171078967 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 (171079981) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64346 + ... + 66951.

It is an arithmetic number, because the mean of its divisors is an integer number (42803148).

Almost surely, 2^171079991 is an apocalyptic number.

171079991 is a deficient number, since it is larger than the sum of its proper divisors (132601).

171079991 is a wasteful number, since it uses less digits than its factorization.

171079991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132600.

The product of its (nonzero) digits is 35721, while the sum is 44.

The square root of 171079991 is about 13079.7550053508. The cubic root of 171079991 is about 555.1364445526.

The spelling of 171079991 in words is "one hundred seventy-one million, seventy-nine thousand, nine hundred ninety-one".