991489 has 8 divisors (see below), whose sum is σ = 1031168. Its totient is φ = 952560.

The previous prime is 991483. The next prime is 991493. The reversal of 991489 is 984199.

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 991489 - 2¹¹ = 989441 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991483) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4594 + ... + 4804.

It is an arithmetic number, because the mean of its divisors is an integer number (128896).

2⁹⁹¹⁴⁸⁹ is an apocalyptic number.

It is an amenable number.

991489 is a deficient number, since it is larger than the sum of its proper divisors (39679).

991489 is a wasteful number, since it uses less digits than its factorization.

991489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 375.

The product of its digits is 23328, while the sum is 40.

The square root of 991489 is about 995.7354066217. The cubic root of 991489 is about 99.7154913157.

The spelling of 991489 in words is "nine hundred ninety-one thousand, four hundred eighty-nine".