321604 has 24 divisors (see below), whose sum is σ = 603288. Its totient is φ = 149760.

The previous prime is 321593. The next prime is 321611. The reversal of 321604 is 406123.

321604 = T₃₉₉ + T₄₀₀ + ... + T₄₀₂.

321604 is an esthetic number in base 15, because in such base its adjacent digits differ by 1.

It can be written as a sum of positive squares in 4 ways, for example, as 61504 + 260100 = 248^2 + 510^2 .

It is an unprimeable number.

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, 6042 + ... + 6094.

It is an arithmetic number, because the mean of its divisors is an integer number (25137).

2³²¹⁶⁰⁴ is an apocalyptic number.

It is an amenable number.

321604 is a deficient number, since it is larger than the sum of its proper divisors (281684).

321604 is a wasteful number, since it uses less digits than its factorization.

321604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135 (or 133 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 321604 is about 567.1014018674. The cubic root of 321604 is about 68.5131308410.

Adding to 321604 its reverse (406123), we get a palindrome (727727).

The spelling of 321604 in words is "three hundred twenty-one thousand, six hundred four".