4040405 has 4 divisors (see below), whose sum is σ = 4848492. Its totient is φ = 3232320.

The previous prime is 4040401. The next prime is 4040411. The reversal of 4040405 is 5040404.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2910436 + 1129969 = 1706^2 + 1063^2 .

It is not a de Polignac number, because 4040405 - 2² = 4040401 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4040401) 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, 404036 + ... + 404045.

It is an arithmetic number, because the mean of its divisors is an integer number (1212123).

Almost surely, 2^4040405 is an apocalyptic number.

It is an amenable number.

4040405 is a deficient number, since it is larger than the sum of its proper divisors (808087).

4040405 is an equidigital number, since it uses as much as digits as its factorization.

4040405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 808086.

The product of its (nonzero) digits is 320, while the sum is 17.

The square root of 4040405 is about 2010.0758692149. The cubic root of 4040405 is about 159.2728067150.

Adding to 4040405 its reverse (5040404), we get a palindrome (9080809).

Subtracting 4040405 from its reverse (5040404), we obtain a palindrome (999999).

The spelling of 4040405 in words is "four million, forty thousand, four hundred five".