9789 has 8 divisors (see below), whose sum is σ = 14112. Its totient is φ = 6000.

The previous prime is 9787. The next prime is 9791. The reversal of 9789 is 9879.

It is an interprime number because it is at equal distance from previous prime (9787) and next prime (9791).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 9789 - 2¹ = 9787 is a prime.

9789 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9781) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 87 + ... + 164.

It is an arithmetic number, because the mean of its divisors is an integer number (1764).

2⁹⁷⁸⁹ is an apocalyptic number.

It is an amenable number.

9789 is a deficient number, since it is larger than the sum of its proper divisors (4323).

9789 is a wasteful number, since it uses less digits than its factorization.

9789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 267.

The product of its digits is 4536, while the sum is 33.

The square root of 9789 is about 98.9393753770. The cubic root of 9789 is about 21.3917399047.

Subtracting from 9789 its product of digits (4536), we obtain a triangular number (5253 = T₁₀₂).

The spelling of 9789 in words is "nine thousand, seven hundred eighty-nine".