9825 has 12 divisors (see below), whose sum is σ = 16368. Its totient is φ = 5200.

The previous prime is 9817. The next prime is 9829. The reversal of 9825 is 5289.

It is not a de Polignac number, because 9825 - 2³ = 9817 is a prime.

Its product of digits (720) is a multiple of the sum of its prime factors (144).

It is a nialpdrome in base 11.

It is a junction number, because it is equal to n+sod(n) for n = 9795 and 9804.

It is not an unprimeable number, because it can be changed into a prime (9829) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10 + ... + 140.

It is an arithmetic number, because the mean of its divisors is an integer number (1364).

2⁹⁸²⁵ is an apocalyptic number.

It is an amenable number.

9825 is a deficient number, since it is larger than the sum of its proper divisors (6543).

9825 is a wasteful number, since it uses less digits than its factorization.

It is an anagram of its base 12 representation: 9825 = (5829)₁₂.

9825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144 (or 139 counting only the distinct ones).

The product of its digits is 720, while the sum is 24.

The square root of 9825 is about 99.1211380080. The cubic root of 9825 is about 21.4179312255.

Subtracting from 9825 its sum of digits (24), we obtain a square (9801 = 99²).

The spelling of 9825 in words is "nine thousand, eight hundred twenty-five".