321609 has 16 divisors (see below), whose sum is σ = 460800. Its totient is φ = 199056.

The previous prime is 321593. The next prime is 321611. The reversal of 321609 is 906123.

321609 is digitally balanced in base 7, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 321609 - 2⁴ = 321593 is a prime.

321609 is strictly pandigital in base 7.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (321619) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4032 + ... + 4110.

It is an arithmetic number, because the mean of its divisors is an integer number (28800).

2³²¹⁶⁰⁹ is an apocalyptic number.

It is an amenable number.

321609 is a deficient number, since it is larger than the sum of its proper divisors (139191).

321609 is a wasteful number, since it uses less digits than its factorization.

321609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164.

The product of its (nonzero) digits is 324, while the sum is 21.

The square root of 321609 is about 567.1058102330. The cubic root of 321609 is about 68.5134858986.

It can be divided in two parts, 3 and 21609, that added together give a palindrome (21612).

The spelling of 321609 in words is "three hundred twenty-one thousand, six hundred nine".