2001908605 has 4 divisors (see below), whose sum is σ = 2402290332. Its totient is φ = 1601526880.

The previous prime is 2001908591. The next prime is 2001908617. The reversal of 2001908605 is 5068091002.

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 476068761 + 1525839844 = 21819^2 + 39062^2 .

It is not a de Polignac number, because 2001908605 - 2⁹ = 2001908093 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 200190856 + ... + 200190865.

It is an arithmetic number, because the mean of its divisors is an integer number (600572583).

Almost surely, 2^2001908605 is an apocalyptic number.

It is an amenable number.

2001908605 is a deficient number, since it is larger than the sum of its proper divisors (400381727).

2001908605 is an equidigital number, since it uses as much as digits as its factorization.

2001908605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 400381726.

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 2001908605 is about 44742.6933141044. The cubic root of 2001908605 is about 1260.3217044093.

Adding to 2001908605 its reverse (5068091002), we get a palindrome (7069999607).

The spelling of 2001908605 in words is "two billion, one million, nine hundred eight thousand, six hundred five".