321998 has 8 divisors (see below), whose sum is σ = 487080. Its totient is φ = 159640.

The previous prime is 321991. The next prime is 322001. The reversal of 321998 is 899123.

321998 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (321991) by changing a digit.

321998 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 353 + ... + 876.

It is an arithmetic number, because the mean of its divisors is an integer number (60885).

2³²¹⁹⁹⁸ is an apocalyptic number.

321998 is a deficient number, since it is larger than the sum of its proper divisors (165082).

321998 is a wasteful number, since it uses less digits than its factorization.

321998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1362.

The product of its digits is 3888, while the sum is 32.

The square root of 321998 is about 567.4486760933. The cubic root of 321998 is about 68.5410981107.

It can be divided in two parts, 32 and 1998, that multiplied together give a palindrome (63936).

The spelling of 321998 in words is "three hundred twenty-one thousand, nine hundred ninety-eight".