581666 has 8 divisors (see below), whose sum is σ = 918480. Its totient is φ = 275508.

The previous prime is 581663. The next prime is 581683. The reversal of 581666 is 666185.

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

It is a Curzon number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 581666.

It is not an unprimeable number, because it can be changed into a prime (581663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7616 + ... + 7691.

It is an arithmetic number, because the mean of its divisors is an integer number (114810).

2⁵⁸¹⁶⁶⁶ is an apocalyptic number.

581666 is a deficient number, since it is larger than the sum of its proper divisors (336814).

581666 is a wasteful number, since it uses less digits than its factorization.

581666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15328.

The product of its digits is 8640, while the sum is 32.

The square root of 581666 is about 762.6703088491. The cubic root of 581666 is about 83.4752816265.

The spelling of 581666 in words is "five hundred eighty-one thousand, six hundred sixty-six".