405420 has 48 divisors (see below), whose sum is σ = 1179360. Its totient is φ = 103936.

The previous prime is 405413. The next prime is 405437. The reversal of 405420 is 24504.

405420 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 405420.

It is an unprimeable number.

405420 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1624 + ... + 1856.

It is an arithmetic number, because the mean of its divisors is an integer number (24570).

2⁴⁰⁵⁴²⁰ 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 405420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (589680).

405420 is an abundant number, since it is smaller than the sum of its proper divisors (773940).

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

405420 is a wasteful number, since it uses less digits than its factorization.

405420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 274 (or 272 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 15.

The square root of 405420 is about 636.7260007256. The cubic root of 405420 is about 74.0119289267.

405420 divided by its sum of digits (15) gives a triangular number (27028 = T₂₃₂).

Adding to 405420 its reverse (24504), we get a palindrome (429924).

It can be divided in two parts, 40 and 5420, that added together give a triangular number (5460 = T₁₀₄).

The spelling of 405420 in words is "four hundred five thousand, four hundred twenty".