408685 has 4 divisors (see below), whose sum is σ = 490428. Its totient is φ = 326944.

The previous prime is 408677. The next prime is 408689. The reversal of 408685 is 586804.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 114921 + 293764 = 339^2 + 542^2 .

It is a cyclic number.

It is not a de Polignac number, because 408685 - 2³ = 408677 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (408689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40864 + ... + 40873.

It is an arithmetic number, because the mean of its divisors is an integer number (122607).

2⁴⁰⁸⁶⁸⁵ is an apocalyptic number.

It is an amenable number.

408685 is a deficient number, since it is larger than the sum of its proper divisors (81743).

408685 is an equidigital number, since it uses as much as digits as its factorization.

408685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81742.

The product of its (nonzero) digits is 7680, while the sum is 31.

The square root of 408685 is about 639.2847565835. The cubic root of 408685 is about 74.2100799290.

The spelling of 408685 in words is "four hundred eight thousand, six hundred eighty-five".