405500 has 24 divisors (see below), whose sum is σ = 886704. Its totient is φ = 162000.

The previous prime is 405499. The next prime is 405521. The reversal of 405500 is 5504.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 95 + ... + 905.

It is an arithmetic number, because the mean of its divisors is an integer number (36946).

2⁴⁰⁵⁵⁰⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 405500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (443352).

405500 is an abundant number, since it is smaller than the sum of its proper divisors (481204).

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

405500 is a wasteful number, since it uses less digits than its factorization.

405500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 830 (or 818 counting only the distinct ones).

The product of its (nonzero) digits is 100, while the sum is 14.

The square root of 405500 is about 636.7888189973. The cubic root of 405500 is about 74.0167967715.

It can be divided in two parts, 405 and 500, that multiplied together give a square (202500 = 450²).

The spelling of 405500 in words is "four hundred five thousand, five hundred".