11998 has 8 divisors (see below), whose sum is σ = 20592. Its totient is φ = 5136.

The previous prime is 11987. The next prime is 12007. The reversal of 11998 is 89911.

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

It is a plaindrome in base 13.

It is a zygodrome in base 13.

It is a congruent number.

It is an unprimeable number.

11998 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, 415 + ... + 442.

It is an arithmetic number, because the mean of its divisors is an integer number (2574).

2¹¹⁹⁹⁸ is an apocalyptic number.

11998 is a deficient number, since it is larger than the sum of its proper divisors (8594).

11998 is an equidigital number, since it uses as much as digits as its factorization.

11998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 866.

The product of its digits is 648, while the sum is 28.

The square root of 11998 is about 109.5353824113. The cubic root of 11998 is about 22.8930128757.

The spelling of 11998 in words is "eleven thousand, nine hundred ninety-eight".