321408 has 80 divisors (see below), whose sum is σ = 987360. Its totient is φ = 103680.

The previous prime is 321403. The next prime is 321413. The reversal of 321408 is 804123.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (321403) and next prime (321413).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (321403) by changing a digit.

321408 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 9 ways as a sum of consecutive naturals, for example, 10353 + ... + 10383.

It is an arithmetic number, because the mean of its divisors is an integer number (12342).

2³²¹⁴⁰⁸ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 321408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (493680).

321408 is an abundant number, since it is smaller than the sum of its proper divisors (665952).

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

321408 is an equidigital number, since it uses as much as digits as its factorization.

321408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57 (or 36 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 321408 is about 566.9285669289. The cubic root of 321408 is about 68.4992096806.

It can be divided in two parts, 321 and 408, that added together give a 6-th power (729 = 3⁶).

The spelling of 321408 in words is "three hundred twenty-one thousand, four hundred eight".