409440 has 48 divisors (see below), whose sum is σ = 1291248. Its totient is φ = 109056.

The previous prime is 409433. The next prime is 409441. The reversal of 409440 is 44904.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (48).

It is a super-2 number, since 2×409440² = 335282227200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (409441) 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, 54 + ... + 906.

It is an arithmetic number, because the mean of its divisors is an integer number (26901).

2⁴⁰⁹⁴⁴⁰ is an apocalyptic number.

409440 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 409440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (645624).

409440 is an abundant number, since it is smaller than the sum of its proper divisors (881808).

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

409440 is a wasteful number, since it uses less digits than its factorization.

409440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 871 (or 863 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 409440 is about 639.8749877906. The cubic root of 409440 is about 74.2557501017.

The spelling of 409440 in words is "four hundred nine thousand, four hundred forty".