201611601 has 9 divisors (see below), whose sum is σ = 291278299. Its totient is φ = 134379336.

The previous prime is 201611591. The next prime is 201611609. The reversal of 201611601 is 106116102.

The square root of 201611601 is 14199.

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

201611601 is a `hidden beast` number, since 2 + 0 + 1 + 61 + 1 + 601 = 666.

It can be written as a sum of positive squares in only one way, i.e., 35820225 + 165791376 = 5985^2 + 12876^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 201611601 - 2⁹ = 201611089 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (201611609) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 40231 + ... + 44963.

Almost surely, 2^201611601 is an apocalyptic number.

201611601 is the 14199-th square number.

201611601 is the 7100-th centered octagonal number.

It is an amenable number.

201611601 is a deficient number, since it is larger than the sum of its proper divisors (89666698).

201611601 is an frugal number, since it uses more digits than its factorization.

201611601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9472 (or 4736 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The cubic root of 201611601 is about 586.3701306064.

Adding to 201611601 its reverse (106116102), we get a palindrome (307727703).

The spelling of 201611601 in words is "two hundred one million, six hundred eleven thousand, six hundred one".