405556 has 12 divisors (see below), whose sum is σ = 723492. Its totient is φ = 198848.

The previous prime is 405553. The next prime is 405577. The reversal of 405556 is 655504.

It can be written as a sum of positive squares in 2 ways, for example, as 324900 + 80656 = 570^2 + 284^2 .

It is a plaindrome in base 11.

It is a self number, because there is not a number n which added to its sum of digits gives 405556.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (405553) 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, 745 + ... + 1168.

It is an arithmetic number, because the mean of its divisors is an integer number (60291).

2⁴⁰⁵⁵⁵⁶ is an apocalyptic number.

It is an amenable number.

405556 is a deficient number, since it is larger than the sum of its proper divisors (317936).

405556 is a wasteful number, since it uses less digits than its factorization.

405556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1970 (or 1968 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 25.

The square root of 405556 is about 636.8327881006. The cubic root of 405556 is about 74.0202038819.

It can be divided in two parts, 405 and 556, that added together give a square (961 = 31²).

The spelling of 405556 in words is "four hundred five thousand, five hundred fifty-six".