320691 has 8 divisors (see below), whose sum is σ = 488704. Its totient is φ = 183240.

The previous prime is 320687. The next prime is 320693. The reversal of 320691 is 196023.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 320691 - 2² = 320687 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21), and also a Moran number because the ratio is a prime number: 15271 = 320691 / (3 + 2 + 0 + 6 + 9 + 1).

It is a Duffinian number.

320691 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (320693) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7615 + ... + 7656.

It is an arithmetic number, because the mean of its divisors is an integer number (61088).

2³²⁰⁶⁹¹ is an apocalyptic number.

320691 is a deficient number, since it is larger than the sum of its proper divisors (168013).

320691 is a wasteful number, since it uses less digits than its factorization.

320691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15281.

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

The square root of 320691 is about 566.2958590702. The cubic root of 320691 is about 68.4482355294.

The spelling of 320691 in words is "three hundred twenty thousand, six hundred ninety-one".