4000040 has 32 divisors (see below), whose sum is σ = 9819360. Its totient is φ = 1454400.

The previous prime is 4000039. The next prime is 4000043. The reversal of 4000040 is 400004.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (8).

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

It is a junction number, because it is equal to n+sod(n) for n = 3999991 and 4000027.

It is not an unprimeable number, because it can be changed into a prime (4000043) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4106 + ... + 4985.

It is an arithmetic number, because the mean of its divisors is an integer number (306855).

Almost surely, 2^4000040 is an apocalyptic number.

4000040 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

4000040 is an abundant number, since it is smaller than the sum of its proper divisors (5819320).

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

4000040 is a wasteful number, since it uses less digits than its factorization.

4000040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9113 (or 9109 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 8.

The square root of 4000040 is about 2000.0099999750. The cubic root of 4000040 is about 158.7406343287.

Adding to 4000040 its reverse (400004), we get a palindrome (4400044).

The spelling of 4000040 in words is "four million, forty", and thus it is an aban number and an eban number.