201601 has 3 divisors (see below), whose sum is σ = 202051. Its totient is φ = 201152.

The previous prime is 201599. The next prime is 201611. The reversal of 201601 is 106102.

201601 = T₄₄₈ + T₄₄₉.

The square root of 201601 is 449.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 106102 = 2 ⋅53051.

It can be written as a sum of positive squares in only one way, i.e., 123201 + 78400 = 351^2 + 280^2 .

It is not a de Polignac number, because 201601 - 2¹ = 201599 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (201611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 225 + ... + 673.

2²⁰¹⁶⁰¹ is an apocalyptic number.

201601 is the 449-th square number.

201601 is the 225-th centered octagonal number.

It is an amenable number.

201601 is a deficient number, since it is larger than the sum of its proper divisors (450).

201601 is an frugal number, since it uses more digits than its factorization.

201601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 898 (or 449 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 10.

The cubic root of 201601 is about 58.6359853058.

Adding to 201601 its reverse (106102), we get a palindrome (307703).

The spelling of 201601 in words is "two hundred one thousand, six hundred one".