291985 has 8 divisors (see below), whose sum is σ = 365760. Its totient is φ = 223344.

The previous prime is 291983. The next prime is 291997. The reversal of 291985 is 589192.

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

It is a cyclic number.

It is not a de Polignac number, because 291985 - 2¹ = 291983 is a prime.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 291985.

It is not an unprimeable number, because it can be changed into a prime (291983) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1155 + ... + 1384.

It is an arithmetic number, because the mean of its divisors is an integer number (45720).

2²⁹¹⁹⁸⁵ is an apocalyptic number.

It is an amenable number.

291985 is a deficient number, since it is larger than the sum of its proper divisors (73775).

291985 is a wasteful number, since it uses less digits than its factorization.

291985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2567.

The product of its digits is 6480, while the sum is 34.

The square root of 291985 is about 540.3563638933. The cubic root of 291985 is about 66.3417383411.

The spelling of 291985 in words is "two hundred ninety-one thousand, nine hundred eighty-five".