181601 has 4 divisors (see below), whose sum is σ = 207552. Its totient is φ = 155652.

The previous prime is 181553. The next prime is 181603. The reversal of 181601 is 106181.

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 not a de Polignac number, because 181601 - 2⁶ = 181537 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 181601.

It is not an unprimeable number, because it can be changed into a prime (181603) 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, 12965 + ... + 12978.

It is an arithmetic number, because the mean of its divisors is an integer number (51888).

2¹⁸¹⁶⁰¹ is an apocalyptic number.

It is an amenable number.

181601 is a deficient number, since it is larger than the sum of its proper divisors (25951).

181601 is an equidigital number, since it uses as much as digits as its factorization.

181601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25950.

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

The square root of 181601 is about 426.1466883598. The cubic root of 181601 is about 56.6290677149.

Adding to 181601 its reverse (106181), we get a palindrome (287782).

The spelling of 181601 in words is "one hundred eighty-one thousand, six hundred one".