165601 has 2 divisors, whose sum is σ = 165602. Its totient is φ = 165600.

The previous prime is 165589. The next prime is 165611. The reversal of 165601 is 106561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 159201 + 6400 = 399^2 + 80^2 .

It is a cyclic number.

It is not a de Polignac number, because 165601 - 2⁵ = 165569 is a prime.

It is a Chen prime.

It is a pancake number, because a pancake can be divided into 165601 parts by 575 straight cuts.

It is not a weakly prime, because it can be changed into another prime (165611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82800 + 82801.

It is an arithmetic number, because the mean of its divisors is an integer number (82801).

2¹⁶⁵⁶⁰¹ is an apocalyptic number.

It is an amenable number.

165601 is a deficient number, since it is larger than the sum of its proper divisors (1).

165601 is an equidigital number, since it uses as much as digits as its factorization.

165601 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 165601 is about 406.9410276686. The cubic root of 165601 is about 54.9145781417.

It can be divided in two parts, 16560 and 1, that added together give a palindrome (16561).

The spelling of 165601 in words is "one hundred sixty-five thousand, six hundred one".