161011 has 4 divisors (see below), whose sum is σ = 163800. Its totient is φ = 158224.

The previous prime is 161009. The next prime is 161017. The reversal of 161011 is 110161.

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 161011 - 2¹ = 161009 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 11.

It is not an unprimeable number, because it can be changed into a prime (161017) 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 3 ways as a sum of consecutive naturals, for example, 1306 + ... + 1423.

It is an arithmetic number, because the mean of its divisors is an integer number (40950).

2¹⁶¹⁰¹¹ is an apocalyptic number.

161011 is a deficient number, since it is larger than the sum of its proper divisors (2789).

161011 is an equidigital number, since it uses as much as digits as its factorization.

161011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2788.

The product of its (nonzero) digits is 6, while the sum is 10.

The square root of 161011 is about 401.2617599523. The cubic root of 161011 is about 54.4024571771.

Adding to 161011 its reverse (110161), we get a palindrome (271172).

The spelling of 161011 in words is "one hundred sixty-one thousand, eleven".