172081 has 16 divisors (see below), whose sum is σ = 222208.
Its totient is φ = 129600.
The previous prime is 172079. The next prime is 172093. The reversal of 172081 is 180271.
It is a 2-Lehmer number, since φ(172081) divides (172081-1)2.
It is a cyclic number.
It is a Carmichael number.
It is not a de Polignac number, because 172081 - 21 = 172079 is a prime.
It is a super-2 number, since 2×1720812 = 59223741122, which contains 22 as substring.
It is a deceptive number, since it divides R172080.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (172001) by changing a digit.
It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2791 + ... + 2851.
It is an arithmetic number, because the mean of its divisors is an integer number (13888).
It is a Poulet number, since it divides 2172080-1.
2172081 is an apocalyptic number.
172081 is the 240-th hex number.
It is an amenable number.
172081 is a deficient number, since it is larger than the sum of its proper divisors (50127).
172081 is a wasteful number, since it uses less digits than its factorization.
172081 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 112.
The product of its (nonzero) digits is 112, while the sum is 19.
The square root of 172081 is about 414.8264697437.
The cubic root of 172081 is about 55.6217062393.
The spelling of 172081 in words is "one hundred seventy-two thousand, eighty-one".