393805 has 16 divisors (see below), whose sum is σ = 517104. Its totient is φ = 286720.

The previous prime is 393797. The next prime is 393847. The reversal of 393805 is 508393.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 101124 + 292681 = 318^2 + 541^2 .

It is not a de Polignac number, because 393805 - 2³ = 393797 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3429 + ... + 3541.

It is an arithmetic number, because the mean of its divisors is an integer number (32319).

2³⁹³⁸⁰⁵ is an apocalyptic number.

It is an amenable number.

393805 is a deficient number, since it is larger than the sum of its proper divisors (123299).

393805 is a wasteful number, since it uses less digits than its factorization.

393805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 176.

The product of its (nonzero) digits is 3240, while the sum is 28.

The square root of 393805 is about 627.5388434193. The cubic root of 393805 is about 73.2982729558.

It can be divided in two parts, 39 and 3805, that added together give a square (3844 = 62²).

The spelling of 393805 in words is "three hundred ninety-three thousand, eight hundred five".