163998 has 16 divisors (see below), whose sum is σ = 364560. Its totient is φ = 54648.

The previous prime is 163997. The next prime is 164011. The reversal of 163998 is 899361.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (163991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1465 + ... + 1572.

It is an arithmetic number, because the mean of its divisors is an integer number (22785).

2¹⁶³⁹⁹⁸ is an apocalyptic number.

163998 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

163998 is an abundant number, since it is smaller than the sum of its proper divisors (200562).

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

163998 is a wasteful number, since it uses less digits than its factorization.

163998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3048 (or 3042 counting only the distinct ones).

The product of its digits is 11664, while the sum is 36.

The square root of 163998 is about 404.9666652948. The cubic root of 163998 is about 54.7368142388.

The spelling of 163998 in words is "one hundred sixty-three thousand, nine hundred ninety-eight".