163989 has 24 divisors (see below), whose sum is σ = 287040. Its totient is φ = 88128.

The previous prime is 163987. The next prime is 163991. The reversal of 163989 is 989361.

It is an interprime number because it is at equal distance from previous prime (163987) and next prime (163991).

It is not a de Polignac number, because 163989 - 2¹ = 163987 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (163981) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1129 + ... + 1265.

It is an arithmetic number, because the mean of its divisors is an integer number (11960).

2¹⁶³⁹⁸⁹ is an apocalyptic number.

163989 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

163989 is a deficient number, since it is larger than the sum of its proper divisors (123051).

163989 is a wasteful number, since it uses less digits than its factorization.

163989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169 (or 166 counting only the distinct ones).

The product of its digits is 11664, while the sum is 36.

The square root of 163989 is about 404.9555531166. The cubic root of 163989 is about 54.7358129251.

Adding to 163989 its sum of digits (36), we get a square (164025 = 405²).

It can be divided in two parts, 1639 and 89, that added together give a cube (1728 = 12³).

The spelling of 163989 in words is "one hundred sixty-three thousand, nine hundred eighty-nine".