320666393 has 8 divisors (see below), whose sum is σ = 339902568. Its totient is φ = 301471744.

The previous prime is 320666341. The next prime is 320666417. The reversal of 320666393 is 393666023.

It can be written as a sum of positive squares in 4 ways, for example, as 121066009 + 199600384 = 11003^2 + 14128^2 .

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

It is not a de Polignac number, because 320666393 - 2¹⁴ = 320650009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (320666693) 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, 6305 + ... + 26097.

It is an arithmetic number, because the mean of its divisors is an integer number (42487821).

Almost surely, 2^320666393 is an apocalyptic number.

It is an amenable number.

320666393 is a deficient number, since it is larger than the sum of its proper divisors (19236175).

320666393 is a wasteful number, since it uses less digits than its factorization.

320666393 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20763.

The product of its (nonzero) digits is 104976, while the sum is 38.

The square root of 320666393 is about 17907.1603834891. The cubic root of 320666393 is about 684.4648477995.

The spelling of 320666393 in words is "three hundred twenty million, six hundred sixty-six thousand, three hundred ninety-three".