4000005 has 24 divisors (see below), whose sum is σ = 7008768. Its totient is φ = 2110176.

The previous prime is 3999971. The next prime is 4000037. The reversal of 4000005 is 5000004.

It is not a de Polignac number, because 4000005 - 2¹⁵ = 3967237 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4204 + ... + 5066.

It is an arithmetic number, because the mean of its divisors is an integer number (292032).

Almost surely, 2^4000005 is an apocalyptic number.

4000005 is a gapful number since it is divisible by the number (45) formed by its first and last digit.

It is an amenable number.

4000005 is a deficient number, since it is larger than the sum of its proper divisors (3008763).

4000005 is a wasteful number, since it uses less digits than its factorization.

4000005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 977 (or 974 counting only the distinct ones).

The product of its (nonzero) digits is 20, while the sum is 9.

The square root of 4000005 is about 2000.0012499996. The cubic root of 4000005 is about 158.7401713385.

Adding to 4000005 its reverse (5000004), we get a palindrome (9000009).

Subtracting 4000005 from its reverse (5000004), we obtain a palindrome (999999).

The spelling of 4000005 in words is "four million, five", and thus it is an aban number.