172108161 has 9 divisors (see below), whose sum is σ = 248657539. Its totient is φ = 114712536.

The previous prime is 172108151. The next prime is 172108163. The reversal of 172108161 is 161801271.

The square root of 172108161 is 13119.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 98903025 + 73205136 = 9945^2 + 8556^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 172108161 - 2⁷ = 172108033 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (172108163) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 37171 + ... + 41543.

Almost surely, 2^172108161 is an apocalyptic number.

172108161 is the 13119-th square number.

172108161 is the 6560-th centered octagonal number.

It is an amenable number.

172108161 is a deficient number, since it is larger than the sum of its proper divisors (76549378).

172108161 is an frugal number, since it uses more digits than its factorization.

172108161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8752 (or 4376 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 27.

The cubic root of 172108161 is about 556.2463250020.

The spelling of 172108161 in words is "one hundred seventy-two million, one hundred eight thousand, one hundred sixty-one".