40840 has 16 divisors (see below), whose sum is σ = 91980. Its totient is φ = 16320.

The previous prime is 40829. The next prime is 40841. The reversal of 40840 is 4804.

40840 = 45² + 46² + ... + 59².

40840 is nontrivially palindromic in base 7.

40840 is digitally balanced in base 2 and base 6, because in such bases it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 40804 + 36 = 202^2 + 6^2 .

40840 is strictly pandigital in base 6.

It is not an unprimeable number, because it can be changed into a prime (40841) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 471 + ... + 550.

2⁴⁰⁸⁴⁰ is an apocalyptic number.

40840 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

40840 is an abundant number, since it is smaller than the sum of its proper divisors (51140).

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 (45990).

40840 is a wasteful number, since it uses less digits than its factorization.

40840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1032 (or 1028 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 40840 is about 202.0890892651. The cubic root of 40840 is about 34.4372590708.

The spelling of 40840 in words is "forty thousand, eight hundred forty".