161811 has 16 divisors (see below), whose sum is σ = 258720. Its totient is φ = 99360.

The previous prime is 161807. The next prime is 161831. The reversal of 161811 is 118161.

161811 = 11³ + 12³ + ... + 28³.

It is not a de Polignac number, because 161811 - 2² = 161807 is a prime.

It is a hoax number, since the sum of its digits (18) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (161831) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 121 + ... + 581.

It is an arithmetic number, because the mean of its divisors is an integer number (16170).

2¹⁶¹⁸¹¹ is an apocalyptic number.

161811 is a deficient number, since it is larger than the sum of its proper divisors (96909).

161811 is a wasteful number, since it uses less digits than its factorization.

161811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 483 (or 477 counting only the distinct ones).

The product of its digits is 48, while the sum is 18.

The square root of 161811 is about 402.2573802928. The cubic root of 161811 is about 54.4924097950.

Adding to 161811 its reverse (118161), we get a palindrome (279972).

The spelling of 161811 in words is "one hundred sixty-one thousand, eight hundred eleven".