405840380 has 96 divisors (see below), whose sum is σ = 991872000. Its totient is φ = 137928960.

The previous prime is 405840377. The next prime is 405840431. The reversal of 405840380 is 83048504.

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 31 ways as a sum of consecutive naturals, for example, 329606 + ... + 330834.

It is an arithmetic number, because the mean of its divisors is an integer number (10332000).

Almost surely, 2^405840380 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 405840380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (495936000).

405840380 is an abundant number, since it is smaller than the sum of its proper divisors (586031620).

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

405840380 is a wasteful number, since it uses less digits than its factorization.

405840380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1347 (or 1345 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 32.

The square root of 405840380 is about 20145.4803864291. The cubic root of 405840380 is about 740.3750107997.

Adding to 405840380 its reverse (83048504), we get a palindrome (488888884).

The spelling of 405840380 in words is "four hundred five million, eight hundred forty thousand, three hundred eighty".