405856 has 24 divisors (see below), whose sum is σ = 872424. Its totient is φ = 184320.

The previous prime is 405829. The next prime is 405857. The reversal of 405856 is 658504.

405856 = T₁₄₃ + T₁₄₄ + ... + T₁₇₄.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (405857) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 225 + ... + 928.

It is an arithmetic number, because the mean of its divisors is an integer number (36351).

2⁴⁰⁵⁸⁵⁶ is an apocalyptic number.

It is an amenable number.

405856 is an abundant number, since it is smaller than the sum of its proper divisors (466568).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

405856 is a wasteful number, since it uses less digits than its factorization.

405856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1174 (or 1166 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 28.

The square root of 405856 is about 637.0682851940. The cubic root of 405856 is about 74.0384509205.

It can be divided in two parts, 4058 and 56, that added together give a palindrome (4114).

The spelling of 405856 in words is "four hundred five thousand, eight hundred fifty-six".