158181 has 4 divisors (see below), whose sum is σ = 210912. Its totient is φ = 105452.

The previous prime is 158161. The next prime is 158189. The reversal of 158181 is 181851.

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, and also an emirpimes, since its reverse is a distinct semiprime: 181851 = 3 ⋅60617.

It is a cyclic number.

It is not a de Polignac number, because 158181 - 2⁹ = 157669 is a prime.

It is a super-2 number, since 2×158181² = 50042457522, which contains 22 as substring.

It is a D-number.

It is a Curzon number.

158181 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (158189) 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, 26361 + ... + 26366.

It is an arithmetic number, because the mean of its divisors is an integer number (52728).

2¹⁵⁸¹⁸¹ is an apocalyptic number.

It is an amenable number.

158181 is a deficient number, since it is larger than the sum of its proper divisors (52731).

158181 is an equidigital number, since it uses as much as digits as its factorization.

158181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52730.

The product of its digits is 320, while the sum is 24.

The square root of 158181 is about 397.7197505782. The cubic root of 158181 is about 54.0818375031.

The spelling of 158181 in words is "one hundred fifty-eight thousand, one hundred eighty-one".