321688 has 16 divisors (see below), whose sum is σ = 612000. Its totient is φ = 158496.

The previous prime is 321679. The next prime is 321707. The reversal of 321688 is 886123.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 378 + ... + 886.

It is an arithmetic number, because the mean of its divisors is an integer number (38250).

2³²¹⁶⁸⁸ is an apocalyptic number.

It is an amenable number.

321688 is a deficient number, since it is larger than the sum of its proper divisors (290312).

321688 is a wasteful number, since it uses less digits than its factorization.

321688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 594 (or 590 counting only the distinct ones).

The product of its digits is 2304, while the sum is 28.

The square root of 321688 is about 567.1754578611. The cubic root of 321688 is about 68.5190953211.

The spelling of 321688 in words is "three hundred twenty-one thousand, six hundred eighty-eight".