169989 has 4 divisors (see below), whose sum is σ = 226656. Its totient is φ = 113324.

The previous prime is 169987. The next prime is 169991. The reversal of 169989 is 989961.

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 an interprime number because it is at equal distance from previous prime (169987) and next prime (169991).

It is a cyclic number.

It is not a de Polignac number, because 169989 - 2¹ = 169987 is a prime.

It is a D-number.

It is a plaindrome in base 15.

It is a self number, because there is not a number n which added to its sum of digits gives 169989.

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 169989.

It is not an unprimeable number, because it can be changed into a prime (169987) 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, 28329 + ... + 28334.

It is an arithmetic number, because the mean of its divisors is an integer number (56664).

2¹⁶⁹⁹⁸⁹ is an apocalyptic number.

It is an amenable number.

169989 is a deficient number, since it is larger than the sum of its proper divisors (56667).

169989 is an equidigital number, since it uses as much as digits as its factorization.

169989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56666.

The product of its digits is 34992, while the sum is 42.

The square root of 169989 is about 412.2972228866. The cubic root of 169989 is about 55.3953877135.

The spelling of 169989 in words is "one hundred sixty-nine thousand, nine hundred eighty-nine".