201666 has 32 divisors (see below), whose sum is σ = 446400. Its totient is φ = 60480.

The previous prime is 201661. The next prime is 201667. The reversal of 201666 is 666102.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 201666.

It is not an unprimeable number, because it can be changed into a prime (201661) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3276 + ... + 3336.

It is an arithmetic number, because the mean of its divisors is an integer number (13950).

2²⁰¹⁶⁶⁶ is an apocalyptic number.

201666 is an abundant number, since it is smaller than the sum of its proper divisors (244734).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

201666 is a wasteful number, since it uses less digits than its factorization.

201666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114.

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 201666 is about 449.0723772400. The cubic root of 201666 is about 58.6422864146.

Adding to 201666 its reverse (666102), we get a palindrome (867768).

The spelling of 201666 in words is "two hundred one thousand, six hundred sixty-six".