2005405 has 8 divisors (see below), whose sum is σ = 2548152. Its totient is φ = 1509888.

The previous prime is 2005397. The next prime is 2005417. The reversal of 2005405 is 5045002.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 95481 + 1909924 = 309^2 + 1382^2 .

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 2005405 - 2³ = 2005397 is a prime.

It is a Duffinian number.

2005405 is a lucky number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11712 + ... + 11881.

It is an arithmetic number, because the mean of its divisors is an integer number (318519).

2^2005405 is an apocalyptic number.

It is an amenable number.

2005405 is a deficient number, since it is larger than the sum of its proper divisors (542747).

2005405 is a wasteful number, since it uses less digits than its factorization.

2005405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23615.

The product of its (nonzero) digits is 200, while the sum is 16.

The square root of 2005405 is about 1416.1232291012. The cubic root of 2005405 is about 126.1055007879.

The spelling of 2005405 in words is "two million, five thousand, four hundred five".