408240 has 140 divisors (see below), whose sum is σ = 1626384. Its totient is φ = 93312.

The previous prime is 408229. The next prime is 408241. The reversal of 408240 is 42804.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (140).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is not an unprimeable number, because it can be changed into a prime (408241) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 58317 + ... + 58323.

2⁴⁰⁸²⁴⁰ is an apocalyptic number.

408240 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 408240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (813192).

408240 is an abundant number, since it is smaller than the sum of its proper divisors (1218144).

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

408240 is an equidigital number, since it uses as much as digits as its factorization.

408240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38 (or 17 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

The square root of 408240 is about 638.9366165748. The cubic root of 408240 is about 74.1831353966.

The spelling of 408240 in words is "four hundred eight thousand, two hundred forty".