165173971 has 4 divisors (see below), whose sum is σ = 172355472. Its totient is φ = 157992472.

The previous prime is 165173959. The next prime is 165173977. The reversal of 165173971 is 179371561.

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 165173971 - 2⁷ = 165173843 is a prime.

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 Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165173977) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3590716 + ... + 3590761.

It is an arithmetic number, because the mean of its divisors is an integer number (43088868).

Almost surely, 2^165173971 is an apocalyptic number.

165173971 is a deficient number, since it is larger than the sum of its proper divisors (7181501).

165173971 is an equidigital number, since it uses as much as digits as its factorization.

165173971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7181500.

The product of its digits is 39690, while the sum is 40.

The square root of 165173971 is about 12852.0026065979. The cubic root of 165173971 is about 548.6733546611.

The spelling of 165173971 in words is "one hundred sixty-five million, one hundred seventy-three thousand, nine hundred seventy-one".