181801 has 4 divisors (see below), whose sum is σ = 188100. Its totient is φ = 175504.

The previous prime is 181789. The next prime is 181813. The reversal of 181801 is 108181.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 108181 = 251 ⋅431.

It is an interprime number because it is at equal distance from previous prime (181789) and next prime (181813).

It can be written as a sum of positive squares in 2 ways, for example, as 76176 + 105625 = 276^2 + 325^2 .

It is a cyclic number.

It is not a de Polignac number, because 181801 - 2¹⁵ = 149033 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (181871) 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, 3106 + ... + 3163.

It is an arithmetic number, because the mean of its divisors is an integer number (47025).

2¹⁸¹⁸⁰¹ is an apocalyptic number.

It is an amenable number.

181801 is a deficient number, since it is larger than the sum of its proper divisors (6299).

181801 is an equidigital number, since it uses as much as digits as its factorization.

181801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6298.

The product of its (nonzero) digits is 64, while the sum is 19.

The square root of 181801 is about 426.3812847675. The cubic root of 181801 is about 56.6498489116.

Adding to 181801 its reverse (108181), we get a palindrome (289982).

It can be divided in two parts, 18180 and 1, that added together give a palindrome (18181).

The spelling of 181801 in words is "one hundred eighty-one thousand, eight hundred one".