400440405 has 16 divisors (see below), whose sum is σ = 649483200. Its totient is φ = 210642048.

The previous prime is 400440401. The next prime is 400440421. The reversal of 400440405 is 504044004.

It is not a de Polignac number, because 400440405 - 2² = 400440401 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400440401) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 181755 + ... + 183944.

It is an arithmetic number, because the mean of its divisors is an integer number (40592700).

Almost surely, 2^400440405 is an apocalyptic number.

It is an amenable number.

400440405 is a deficient number, since it is larger than the sum of its proper divisors (249042795).

400440405 is a wasteful number, since it uses less digits than its factorization.

400440405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 365780.

The product of its (nonzero) digits is 1280, while the sum is 21.

The square root of 400440405 is about 20011.0070960959. The cubic root of 400440405 is about 737.0766115288.

Adding to 400440405 its reverse (504044004), we get a palindrome (904484409).

The spelling of 400440405 in words is "four hundred million, four hundred forty thousand, four hundred five".