321618 has 24 divisors (see below), whose sum is σ = 708624. Its totient is φ = 97240.

The previous prime is 321617. The next prime is 321619. The reversal of 321618 is 816123.

It is an interprime number because it is at equal distance from previous prime (321617) and next prime (321619).

It is an alternating number because its digits alternate between odd and even.

It is a junction number, because it is equal to n+sod(n) for n = 321594 and 321603.

It is not an unprimeable number, because it can be changed into a prime (321611) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 505 + ... + 947.

It is an arithmetic number, because the mean of its divisors is an integer number (29526).

2³²¹⁶¹⁸ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 321618, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (354312).

321618 is an abundant number, since it is smaller than the sum of its proper divisors (387006).

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

321618 is a wasteful number, since it uses less digits than its factorization.

321618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 470 (or 459 counting only the distinct ones).

The product of its digits is 288, while the sum is 21.

The square root of 321618 is about 567.1137452046. The cubic root of 321618 is about 68.5141249931.

It can be divided in two parts, 321 and 618, that added together give a palindrome (939).

The spelling of 321618 in words is "three hundred twenty-one thousand, six hundred eighteen".