9980 has 12 divisors (see below), whose sum is σ = 21000. Its totient is φ = 3984.

The previous prime is 9973. The next prime is 10007. The reversal of 9980 is 899.

9980 = T₁₆ + T₁₇ + ... + T₃₉.

It is a happy number.

It is an Ulam number.

It is a plaindrome in base 14.

It is a nialpdrome in base 10 and base 11.

It is a congruent number.

It is an unprimeable number.

9980 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 230 + ... + 269.

It is an arithmetic number, because the mean of its divisors is an integer number (1750).

2⁹⁹⁸⁰ is an apocalyptic number.

It is an amenable number.

9980 is an abundant number, since it is smaller than the sum of its proper divisors (11020).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10500).

9980 is a wasteful number, since it uses less digits than its factorization.

9980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 508 (or 506 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 26.

The square root of 9980 is about 99.8999499499. The cubic root of 9980 is about 21.5299744165.

It can be divided in two parts, 9 and 980, that added together give a palindrome (989).

The spelling of 9980 in words is "nine thousand, nine hundred eighty".