171571945 has 4 divisors (see below), whose sum is σ = 205886340. Its totient is φ = 137257552.

The previous prime is 171571943. The next prime is 171571969. The reversal of 171571945 is 549175171.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 45414121 + 126157824 = 6739^2 + 11232^2 .

It is a cyclic number.

It is not a de Polignac number, because 171571945 - 2¹ = 171571943 is a prime.

It is a super-2 number, since 2×171571945² = 58873864622166050, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 171571898 and 171571907.

It is not an unprimeable number, because it can be changed into a prime (171571943) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17157190 + ... + 17157199.

It is an arithmetic number, because the mean of its divisors is an integer number (51471585).

Almost surely, 2^171571945 is an apocalyptic number.

It is an amenable number.

171571945 is a deficient number, since it is larger than the sum of its proper divisors (34314395).

171571945 is an equidigital number, since it uses as much as digits as its factorization.

171571945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34314394.

The product of its digits is 44100, while the sum is 40.

The square root of 171571945 is about 13098.5474385521. The cubic root of 171571945 is about 555.6680481906.

It can be divided in two parts, 17157 and 1945, that multiplied together give a triangular number (33370365 = T₈₁₆₉).

The spelling of 171571945 in words is "one hundred seventy-one million, five hundred seventy-one thousand, nine hundred forty-five".