393993 has 6 divisors (see below), whose sum is σ = 569114. Its totient is φ = 262656.

The previous prime is 393989. The next prime is 393997. The reversal of 393993 is 399393.

It is an interprime number because it is at equal distance from previous prime (393989) and next prime (393997).

It can be written as a sum of positive squares in only one way, i.e., 227529 + 166464 = 477^2 + 408^2 .

It is not a de Polignac number, because 393993 - 2² = 393989 is a prime.

It is a nude number because it is divisible by every one of its digits.

It is a Duffinian number.

393993 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (393997) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 21880 + ... + 21897.

2³⁹³⁹⁹³ is an apocalyptic number.

It is an amenable number.

393993 is a deficient number, since it is larger than the sum of its proper divisors (175121).

393993 is a wasteful number, since it uses less digits than its factorization.

393993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43783 (or 43780 counting only the distinct ones).

The product of its digits is 19683, while the sum is 36.

The square root of 393993 is about 627.6886170706. The cubic root of 393993 is about 73.3099351431.

The spelling of 393993 in words is "three hundred ninety-three thousand, nine hundred ninety-three".