201566 has 8 divisors (see below), whose sum is σ = 305760. Its totient is φ = 99648.

The previous prime is 201557. The next prime is 201577. The reversal of 201566 is 665102.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 326 + ... + 713.

It is an arithmetic number, because the mean of its divisors is an integer number (38220).

2²⁰¹⁵⁶⁶ is an apocalyptic number.

201566 is a deficient number, since it is larger than the sum of its proper divisors (104194).

201566 is a wasteful number, since it uses less digits than its factorization.

201566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1138.

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 201566 is about 448.9610228071. The cubic root of 201566 is about 58.6325918401.

Adding to 201566 its reverse (665102), we get a palindrome (866668).

It can be divided in two parts, 201 and 566, that added together give a palindrome (767).

The spelling of 201566 in words is "two hundred one thousand, five hundred sixty-six".