9959 has 4 divisors (see below), whose sum is σ = 10416. Its totient is φ = 9504.

The previous prime is 9949. The next prime is 9967. The reversal of 9959 is 9599.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9599 = 29 ⋅331.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9959 is a prime.

It is a Duffinian number.

It is a plaindrome in base 8.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 9959.

It is not an unprimeable number, because it can be changed into a prime (9929) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 194 + ... + 239.

It is an arithmetic number, because the mean of its divisors is an integer number (2604).

2⁹⁹⁵⁹ is an apocalyptic number.

9959 is a deficient number, since it is larger than the sum of its proper divisors (457).

9959 is a wasteful number, since it uses less digits than its factorization.

9959 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 456.

The product of its digits is 3645, while the sum is 32.

The square root of 9959 is about 99.7947894431. The cubic root of 9959 is about 21.5148626276.

The spelling of 9959 in words is "nine thousand, nine hundred fifty-nine".