321689 has 4 divisors (see below), whose sum is σ = 338640. Its totient is φ = 304740.

The previous prime is 321679. The next prime is 321707. The reversal of 321689 is 986123.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 321689 - 2¹² = 317593 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 321689.

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 3 ways as a sum of consecutive naturals, for example, 8447 + ... + 8484.

It is an arithmetic number, because the mean of its divisors is an integer number (84660).

2³²¹⁶⁸⁹ is an apocalyptic number.

It is an amenable number.

321689 is a deficient number, since it is larger than the sum of its proper divisors (16951).

321689 is a wasteful number, since it uses less digits than its factorization.

321689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16950.

The product of its digits is 2592, while the sum is 29.

The square root of 321689 is about 567.1763394219. The cubic root of 321689 is about 68.5191663206.

The spelling of 321689 in words is "three hundred twenty-one thousand, six hundred eighty-nine".