393985 has 4 divisors (see below), whose sum is σ = 472788. Its totient is φ = 315184.

The previous prime is 393977. The next prime is 393989. The reversal of 393985 is 589393.

393985 = T₅₁₁ + T₅₁₂ + T₅₁₃.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 589393 = 7 ⋅84199.

It can be written as a sum of positive squares in 2 ways, for example, as 237169 + 156816 = 487^2 + 396^2 .

It is a cyclic number.

It is not a de Polignac number, because 393985 - 2³ = 393977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (393989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39394 + ... + 39403.

It is an arithmetic number, because the mean of its divisors is an integer number (118197).

2³⁹³⁹⁸⁵ is an apocalyptic number.

393985 is the 513-rd centered triangular number.

It is an amenable number.

393985 is a deficient number, since it is larger than the sum of its proper divisors (78803).

393985 is an equidigital number, since it uses as much as digits as its factorization.

393985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78802.

The product of its digits is 29160, while the sum is 37.

The square root of 393985 is about 627.6822444518. The cubic root of 393985 is about 73.3094389554.

It can be divided in two parts, 393 and 985, that added together give a triangular number (1378 = T₅₂).

The spelling of 393985 in words is "three hundred ninety-three thousand, nine hundred eighty-five".