400421405 has 8 divisors (see below), whose sum is σ = 480886200. Its totient is φ = 320083456.

The previous prime is 400421369. The next prime is 400421407. The reversal of 400421405 is 504124004.

It can be written as a sum of positive squares in 4 ways, for example, as 198838201 + 201583204 = 14101^2 + 14198^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 400421405 - 2⁸ = 400421149 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400421407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24620 + ... + 37509.

It is an arithmetic number, because the mean of its divisors is an integer number (60110775).

Almost surely, 2^400421405 is an apocalyptic number.

It is an amenable number.

400421405 is a deficient number, since it is larger than the sum of its proper divisors (80464795).

400421405 is a wasteful number, since it uses less digits than its factorization.

400421405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63423.

The product of its (nonzero) digits is 640, while the sum is 20.

The square root of 400421405 is about 20010.5323517392. The cubic root of 400421405 is about 737.0649537998.

Adding to 400421405 its reverse (504124004), we get a palindrome (904545409).

The spelling of 400421405 in words is "four hundred million, four hundred twenty-one thousand, four hundred five".