989665 has 4 divisors (see below), whose sum is σ = 1187604. Its totient is φ = 791728.

The previous prime is 989663. The next prime is 989671. The reversal of 989665 is 566989.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 566989 = 41 ⋅13829.

It can be written as a sum of positive squares in 2 ways, for example, as 113569 + 876096 = 337^2 + 936^2 .

It is a cyclic number.

It is not a de Polignac number, because 989665 - 2¹ = 989663 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (989663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 98962 + ... + 98971.

It is an arithmetic number, because the mean of its divisors is an integer number (296901).

2⁹⁸⁹⁶⁶⁵ is an apocalyptic number.

It is an amenable number.

989665 is a deficient number, since it is larger than the sum of its proper divisors (197939).

989665 is a wasteful number, since it uses less digits than its factorization.

989665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 197938.

The product of its digits is 116640, while the sum is 43.

The square root of 989665 is about 994.8190790289. The cubic root of 989665 is about 99.6543063360.

The spelling of 989665 in words is "nine hundred eighty-nine thousand, six hundred sixty-five".