404240 has 40 divisors (see below), whose sum is σ = 976128. Its totient is φ = 155520.

The previous prime is 404221. The next prime is 404249. The reversal of 404240 is 42404.

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

It is not an unprimeable number, because it can be changed into a prime (404249) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 2399 + ... + 2561.

2⁴⁰⁴²⁴⁰ is an apocalyptic number.

404240 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 404240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (488064).

404240 is an abundant number, since it is smaller than the sum of its proper divisors (571888).

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

404240 is a wasteful number, since it uses less digits than its factorization.

404240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 207 (or 201 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 14.

The square root of 404240 is about 635.7987102849. The cubic root of 404240 is about 73.9400537160.

Adding to 404240 its reverse (42404), we get a palindrome (446644).

The spelling of 404240 in words is "four hundred four thousand, two hundred forty", and thus it is an iban number.