2005801081 has 4 divisors (see below), whose sum is σ = 2005903872. Its totient is φ = 2005698292.

The previous prime is 2005801051. The next prime is 2005801103. The reversal of 2005801081 is 1801085002.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1801085002 = 2 ⋅900542501.

It is a cyclic number.

It is not a de Polignac number, because 2005801081 - 2²⁵ = 1972246649 is a prime.

It is a super-2 number, since 2×2005801081² = 8046475953081537122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2005801001) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 12121 + ... + 64486.

It is an arithmetic number, because the mean of its divisors is an integer number (501475968).

Almost surely, 2^2005801081 is an apocalyptic number.

It is an amenable number.

2005801081 is a deficient number, since it is larger than the sum of its proper divisors (102791).

2005801081 is an equidigital number, since it uses as much as digits as its factorization.

2005801081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102790.

The product of its (nonzero) digits is 640, while the sum is 25.

The square root of 2005801081 is about 44786.1706445193. The cubic root of 2005801081 is about 1261.1380247013.

Adding to 2005801081 its reverse (1801085002), we get a palindrome (3806886083).

The spelling of 2005801081 in words is "two billion, five million, eight hundred one thousand, eighty-one".