2001905 has 4 divisors (see below), whose sum is σ = 2402292. Its totient is φ = 1601520.

The previous prime is 2001847. The next prime is 2001911. The reversal of 2001905 is 5091002.

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 1442401 + 559504 = 1201^2 + 748^2 .

It is a de Polignac number, because none of the positive numbers 2^k-2001905 is a prime.

It is a Duffinian 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 3 ways as a sum of consecutive naturals, for example, 200186 + ... + 200195.

It is an arithmetic number, because the mean of its divisors is an integer number (600573).

2^2001905 is an apocalyptic number.

It is an amenable number.

2001905 is a deficient number, since it is larger than the sum of its proper divisors (400387).

2001905 is an equidigital number, since it uses as much as digits as its factorization.

2001905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 400386.

The product of its (nonzero) digits is 90, while the sum is 17.

The square root of 2001905 is about 1414.8869212767. The cubic root of 2001905 is about 126.0320947887.

Adding to 2001905 its reverse (5091002), we get a palindrome (7092907).

The spelling of 2001905 in words is "two million, one thousand, nine hundred five".