171720145 has 16 divisors (see below), whose sum is σ = 224086608. Its totient is φ = 125798400.

The previous prime is 171720089. The next prime is 171720161. The reversal of 171720145 is 541027171.

It can be written as a sum of positive squares in 8 ways, for example, as 5329 + 171714816 = 73^2 + 13104^2 .

It is not a de Polignac number, because 171720145 - 2²¹ = 169622993 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24156 + ... + 30445.

It is an arithmetic number, because the mean of its divisors is an integer number (14005413).

Almost surely, 2^171720145 is an apocalyptic number.

It is an amenable number.

171720145 is a deficient number, since it is larger than the sum of its proper divisors (52366463).

171720145 is a wasteful number, since it uses less digits than its factorization.

171720145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54660.

The product of its (nonzero) digits is 1960, while the sum is 28.

The square root of 171720145 is about 13104.2033332820. The cubic root of 171720145 is about 555.8279933483.

The spelling of 171720145 in words is "one hundred seventy-one million, seven hundred twenty thousand, one hundred forty-five".