2005977781 has 16 divisors (see below), whose sum is σ = 2162692224. Its totient is φ = 1853845504.

The previous prime is 2005977773. The next prime is 2005977797. The reversal of 2005977781 is 1877795002.

It is not a de Polignac number, because 2005977781 - 2³ = 2005977773 is a prime.

It is a super-2 number, since 2×2005977781² = 8047893715731367922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2005957781) 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 15 ways as a sum of consecutive naturals, for example, 231381 + ... + 239893.

It is an arithmetic number, because the mean of its divisors is an integer number (135168264).

Almost surely, 2^2005977781 is an apocalyptic number.

It is an amenable number.

2005977781 is a deficient number, since it is larger than the sum of its proper divisors (156714443).

2005977781 is a wasteful number, since it uses less digits than its factorization.

2005977781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8780.

The product of its (nonzero) digits is 246960, while the sum is 46.

The square root of 2005977781 is about 44788.1433082462. The cubic root of 2005977781 is about 1261.1750567127.

The spelling of 2005977781 in words is "two billion, five million, nine hundred seventy-seven thousand, seven hundred eighty-one".