405986 has 16 divisors (see below), whose sum is σ = 711936. Its totient is φ = 170016.

The previous prime is 405967. The next prime is 405989. The reversal of 405986 is 689504.

It is not an unprimeable number, because it can be changed into a prime (405989) by changing a digit.

405986 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 350 + ... + 966.

It is an arithmetic number, because the mean of its divisors is an integer number (44496).

2⁴⁰⁵⁹⁸⁶ is an apocalyptic number.

405986 is a deficient number, since it is larger than the sum of its proper divisors (305950).

405986 is a wasteful number, since it uses less digits than its factorization.

405986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 673.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 405986 is about 637.1703069039. The cubic root of 405986 is about 74.0463551781.

It can be divided in two parts, 40598 and 6, that added together give a palindrome (40604).

The spelling of 405986 in words is "four hundred five thousand, nine hundred eighty-six".