405840000 has 320 divisors, whose sum is σ = 1433916000. Its totient is φ = 101376000.

The previous prime is 405839969. The next prime is 405840023. The reversal of 405840000 is 48504.

It is a tau number, because it is divible by the number of its divisors (320).

It is a super-2 number, since 2×405840000² = 329412211200000000, which contains 22 as substring.

It is a congruent number.

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 39 ways as a sum of consecutive naturals, for example, 4559956 + ... + 4560044.

Almost surely, 2^405840000 is an apocalyptic number.

405840000 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 405840000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (716958000).

405840000 is an abundant number, since it is smaller than the sum of its proper divisors (1028076000).

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

405840000 is an equidigital number, since it uses as much as digits as its factorization.

405840000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145 (or 118 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 21.

The square root of 405840000 is about 20145.4709550311. The cubic root of 405840000 is about 740.3747797215.

Adding to 405840000 its reverse (48504), we get a palindrome (405888504).

The spelling of 405840000 in words is "four hundred five million, eight hundred forty thousand".