405920 has 48 divisors (see below), whose sum is σ = 997920. Its totient is φ = 155904.

The previous prime is 405917. The next prime is 405947. The reversal of 405920 is 29504.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 405892 and 405901.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 405920.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 6851 + ... + 6909.

It is an arithmetic number, because the mean of its divisors is an integer number (20790).

2⁴⁰⁵⁹²⁰ is an apocalyptic number.

405920 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 405920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (498960).

405920 is an abundant number, since it is smaller than the sum of its proper divisors (592000).

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

405920 is a wasteful number, since it uses less digits than its factorization.

405920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117 (or 109 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 405920 is about 637.1185133082. The cubic root of 405920 is about 74.0423424582.

The spelling of 405920 in words is "four hundred five thousand, nine hundred twenty".