291989 has 4 divisors (see below), whose sum is σ = 301440. Its totient is φ = 282540.

The previous prime is 291983. The next prime is 291997. The reversal of 291989 is 989192.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 291989 - 2¹⁶ = 226453 is a prime.

It is a super-2 number, since 2×291989² = 170515152242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 291989.

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 3 ways as a sum of consecutive naturals, for example, 4679 + ... + 4740.

It is an arithmetic number, because the mean of its divisors is an integer number (75360).

2²⁹¹⁹⁸⁹ is an apocalyptic number.

It is an amenable number.

291989 is a deficient number, since it is larger than the sum of its proper divisors (9451).

291989 is an equidigital number, since it uses as much as digits as its factorization.

291989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9450.

The product of its digits is 11664, while the sum is 38.

The square root of 291989 is about 540.3600651418. The cubic root of 291989 is about 66.3420412856.

The spelling of 291989 in words is "two hundred ninety-one thousand, nine hundred eighty-nine".