161572171 has 4 divisors (see below), whose sum is σ = 168597072. Its totient is φ = 154547272.

The previous prime is 161572163. The next prime is 161572189. The reversal of 161572171 is 171275161.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 161572171 - 2³ = 161572163 is a prime.

It is a super-2 number, since 2×161572171² = 52211132883306482, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161572121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3512416 + ... + 3512461.

It is an arithmetic number, because the mean of its divisors is an integer number (42149268).

Almost surely, 2^161572171 is an apocalyptic number.

161572171 is a deficient number, since it is larger than the sum of its proper divisors (7024901).

161572171 is an equidigital number, since it uses as much as digits as its factorization.

161572171 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7024900.

The product of its digits is 2940, while the sum is 31.

The square root of 161572171 is about 12711.1042399943. The cubic root of 161572171 is about 544.6558678144.

The spelling of 161572171 in words is "one hundred sixty-one million, five hundred seventy-two thousand, one hundred seventy-one".