40240 has 20 divisors (see below), whose sum is σ = 93744. Its totient is φ = 16064.

The previous prime is 40237. The next prime is 40241. The reversal of 40240 is 4204.

It is a tau number, because it is divible by the number of its divisors (20).

It is a Harshad number since it is a multiple of its sum of digits (10).

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (40241) 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 3 ways as a sum of consecutive naturals, for example, 172 + ... + 331.

2⁴⁰²⁴⁰ is an apocalyptic number.

40240 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

40240 is an abundant number, since it is smaller than the sum of its proper divisors (53504).

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46872).

40240 is a wasteful number, since it uses less digits than its factorization.

40240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 516 (or 510 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 10.

The square root of 40240 is about 200.5991026899. The cubic root of 40240 is about 34.2677816275.

Adding to 40240 its reverse (4204), we get a palindrome (44444).

The spelling of 40240 in words is "forty thousand, two hundred forty", and thus it is an iban number.