172091 has 8 divisors (see below), whose sum is σ = 186624. Its totient is φ = 158080.

The previous prime is 172079. The next prime is 172093. The reversal of 172091 is 190271.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 172091 - 2⁶ = 172027 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (172093) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 806 + ... + 996.

It is an arithmetic number, because the mean of its divisors is an integer number (23328).

2¹⁷²⁰⁹¹ is an apocalyptic number.

172091 is a deficient number, since it is larger than the sum of its proper divisors (14533).

172091 is a wasteful number, since it uses less digits than its factorization.

172091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 261.

The product of its (nonzero) digits is 126, while the sum is 20.

The square root of 172091 is about 414.8385228013. The cubic root of 172091 is about 55.6227836511.

It can be divided in two parts, 1720 and 91, that multiplied together give a triangular number (156520 = T₅₅₉).

The spelling of 172091 in words is "one hundred seventy-two thousand, ninety-one".