40008 has 16 divisors (see below), whose sum is σ = 100080. Its totient is φ = 13328.

The previous prime is 39989. The next prime is 40009. The reversal of 40008 is 80004.

It is a Harshad number since it is a multiple of its sum of digits (12).

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

It is an Ulam number.

It is a zygodrome in base 7.

It is a junction number, because it is equal to n+sod(n) for n = 39975 and 40002.

It is not an unprimeable number, because it can be changed into a prime (40009) by changing a digit.

40008 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 810 + ... + 857.

It is an arithmetic number, because the mean of its divisors is an integer number (6255).

2⁴⁰⁰⁰⁸ is an apocalyptic number.

It is an amenable number.

40008 is an abundant number, since it is smaller than the sum of its proper divisors (60072).

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 (50040).

40008 is a wasteful number, since it uses less digits than its factorization.

40008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1676 (or 1672 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 40008 is about 200.0199990001. The cubic root of 40008 is about 34.2017987495.

The spelling of 40008 in words is "forty thousand, eight".