291666 has 8 divisors (see below), whose sum is σ = 583344. Its totient is φ = 97220.

The previous prime is 291661. The next prime is 291677. The reversal of 291666 is 666192.

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

291666 is an admirable number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 291666.

It is not an unprimeable number, because it can be changed into a prime (291661) by changing a digit.

291666 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24300 + ... + 24311.

It is an arithmetic number, because the mean of its divisors is an integer number (72918).

2²⁹¹⁶⁶⁶ is an apocalyptic number.

291666 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

291666 is a wasteful number, since it uses less digits than its factorization.

291666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48616.

The product of its digits is 3888, while the sum is 30.

The square root of 291666 is about 540.0611076536. The cubic root of 291666 is about 66.3175696039.

The spelling of 291666 in words is "two hundred ninety-one thousand, six hundred sixty-six".