9999

Properties by base:

More about this number at Positiv Integers and Number Empire.

The number is not a prime.

Its 4 (3 unique) factors are:
3² = 9
11
101

Its 12 divisors are:
1
3
9
11
33
99
101
303
909
1111
3333
9999
Its aliquote sum is:
5913
makeing it a deficient number.

As Unicode codepoint (since version 1.1) this number represents this character:✏ PENCIL in Dingbats (Source: https://ucdapi.org/unicode/latest/codepoint/dec/9999); HTML: ✏

The number appears at position 762 of the decimal digits of π surrounded by
77130996051870721134999999837297804995105973 Source: The Pi-Search Page

Computations done with Math::BigInt 1.999811 and Math::Pari 2.030523 based on PARI/GP 2.11.3 (elapsed: 852.516ms; cpu: 78.9790000000039ms)