405040 has 40 divisors (see below), whose sum is σ = 968688. Its totient is φ = 157440.

The previous prime is 405037. The next prime is 405047. The reversal of 405040 is 40504.

It is a tau number, because it is divible by the number of its divisors (40).

It is a plaindrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 405040.

It is not an unprimeable number, because it can be changed into a prime (405047) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4839 + ... + 4921.

2⁴⁰⁵⁰⁴⁰ is an apocalyptic number.

405040 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 405040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (484344).

405040 is an abundant number, since it is smaller than the sum of its proper divisors (563648).

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

405040 is a wasteful number, since it uses less digits than its factorization.

405040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 157 (or 151 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 13.

The square root of 405040 is about 636.4275292600. The cubic root of 405040 is about 73.9887979147.

Adding to 405040 its reverse (40504), we get a palindrome (445544).

The spelling of 405040 in words is "four hundred five thousand, forty".