172109 has 8 divisors (see below), whose sum is σ = 205440. Its totient is φ = 140976.

The previous prime is 172097. The next prime is 172127. The reversal of 172109 is 901271.

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 172109 - 2⁴ = 172093 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 (172169) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 374 + ... + 695.

It is an arithmetic number, because the mean of its divisors is an integer number (25680).

2¹⁷²¹⁰⁹ is an apocalyptic number.

It is an amenable number.

172109 is a deficient number, since it is larger than the sum of its proper divisors (33331).

172109 is a wasteful number, since it uses less digits than its factorization.

172109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1099.

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

The square root of 172109 is about 414.8602174227. The cubic root of 172109 is about 55.6247228871.

It can be divided in two parts, 17 and 2109, that multiplied together give a palindrome (35853).

The spelling of 172109 in words is "one hundred seventy-two thousand, one hundred nine".