181541 has 4 divisors (see below), whose sum is σ = 182400. Its totient is φ = 180684.

The previous prime is 181537. The next prime is 181549. The reversal of 181541 is 145181.

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 a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 145181 = 41 ⋅3541.

It is a cyclic number.

It is not a de Polignac number, because 181541 - 2² = 181537 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181549) 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, 140 + ... + 618.

It is an arithmetic number, because the mean of its divisors is an integer number (45600).

2¹⁸¹⁵⁴¹ is an apocalyptic number.

It is an amenable number.

181541 is a deficient number, since it is larger than the sum of its proper divisors (859).

181541 is an equidigital number, since it uses as much as digits as its factorization.

181541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 858.

The product of its digits is 160, while the sum is 20.

The square root of 181541 is about 426.0762842497. The cubic root of 181541 is about 56.6228303808.

The spelling of 181541 in words is "one hundred eighty-one thousand, five hundred forty-one".