1000406405 has 16 divisors (see below), whose sum is σ = 1223914224. Its totient is φ = 784788480.

The previous prime is 1000406399. The next prime is 1000406431. The reversal of 1000406405 is 5046040001.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 78251716 + 922154689 = 8846^2 + 30367^2 .

It is not a de Polignac number, because 1000406405 - 2⁴ = 1000406389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 97919 + ... + 107651.

It is an arithmetic number, because the mean of its divisors is an integer number (76494639).

Almost surely, 2^1000406405 is an apocalyptic number.

It is an amenable number.

1000406405 is a deficient number, since it is larger than the sum of its proper divisors (223507819).

1000406405 is an equidigital number, since it uses as much as digits as its factorization.

1000406405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10136.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 1000406405 is about 31629.2017762067. The cubic root of 1000406405 is about 1000.1354499858.

Adding to 1000406405 its reverse (5046040001), we get a palindrome (6046446406).

The spelling of 1000406405 in words is "one billion, four hundred six thousand, four hundred five".