320686665 has 16 divisors (see below), whose sum is σ = 552568128. Its totient is φ = 157876416.

The previous prime is 320686651. The next prime is 320686673. The reversal of 320686665 is 566686023.

It is not a de Polignac number, because 320686665 - 2¹³ = 320678473 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 822079 + ... + 822468.

It is an arithmetic number, because the mean of its divisors is an integer number (34535508).

Almost surely, 2^320686665 is an apocalyptic number.

It is an amenable number.

320686665 is a deficient number, since it is larger than the sum of its proper divisors (231881463).

320686665 is a wasteful number, since it uses less digits than its factorization.

320686665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1644568.

The product of its (nonzero) digits is 311040, while the sum is 42.

The square root of 320686665 is about 17907.7264051024. The cubic root of 320686665 is about 684.4792710748.

The spelling of 320686665 in words is "three hundred twenty million, six hundred eighty-six thousand, six hundred sixty-five".