405380 has 12 divisors (see below), whose sum is σ = 851340. Its totient is φ = 162144.

The previous prime is 405373. The next prime is 405401. The reversal of 405380 is 83504.

It can be written as a sum of positive squares in 2 ways, for example, as 232324 + 173056 = 482^2 + 416^2 .

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 20269 = 405380 / (4 + 0 + 5 + 3 + 8 + 0).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10115 + ... + 10154.

It is an arithmetic number, because the mean of its divisors is an integer number (70945).

2⁴⁰⁵³⁸⁰ is an apocalyptic number.

It is an amenable number.

405380 is an abundant number, since it is smaller than the sum of its proper divisors (445960).

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

405380 is a wasteful number, since it uses less digits than its factorization.

405380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20278 (or 20276 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 405380 is about 636.6945892655. The cubic root of 405380 is about 74.0094947642.

Adding to 405380 its reverse (83504), we get a palindrome (488884).

The spelling of 405380 in words is "four hundred five thousand, three hundred eighty".