16181 has 4 divisors (see below), whose sum is σ = 17664. Its totient is φ = 14700.

The previous prime is 16141. The next prime is 16183. The reversal of 16181 is 18161.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16181 is a prime.

It is a super-2 number, since 2×16181² = 523649522, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 16181.

It is not an unprimeable number, because it can be changed into a prime (16183) 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, 725 + ... + 746.

It is an arithmetic number, because the mean of its divisors is an integer number (4416).

2¹⁶¹⁸¹ is an apocalyptic number.

16181 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

16181 is a deficient number, since it is larger than the sum of its proper divisors (1483).

16181 is a wasteful number, since it uses less digits than its factorization.

16181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1482.

The product of its digits is 48, while the sum is 17.

The square root of 16181 is about 127.2045596667. The cubic root of 16181 is about 25.2930839777.

It can be divided in two parts, 161 and 81, that multiplied together give a triangular number (13041 = T₁₆₁).

The spelling of 16181 in words is "sixteen thousand, one hundred eighty-one".