161005 has 8 divisors (see below), whose sum is σ = 208152. Its totient is φ = 118848.

The previous prime is 160997. The next prime is 161009. The reversal of 161005 is 500161.

It can be written as a sum of positive squares in 4 ways, for example, as 2601 + 158404 = 51^2 + 398^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 161005 - 2³ = 160997 is a prime.

It is a super-2 number, since 2×161005² = 51845220050, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1174 + ... + 1303.

It is an arithmetic number, because the mean of its divisors is an integer number (26019).

2¹⁶¹⁰⁰⁵ is an apocalyptic number.

It is an amenable number.

161005 is a deficient number, since it is larger than the sum of its proper divisors (47147).

161005 is a wasteful number, since it uses less digits than its factorization.

161005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2495.

The product of its (nonzero) digits is 30, while the sum is 13.

The square root of 161005 is about 401.2542834662. The cubic root of 161005 is about 54.4017814079.

Adding to 161005 its reverse (500161), we get a palindrome (661166).

The spelling of 161005 in words is "one hundred sixty-one thousand, five".