2005551671 has 4 divisors (see below), whose sum is σ = 2013355632. Its totient is φ = 1997747712.

The previous prime is 2005551643. The next prime is 2005551679. The reversal of 2005551671 is 1761555002.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2005551671 - 2³⁰ = 931809847 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2005551679) 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, 3901595 + ... + 3902108.

It is an arithmetic number, because the mean of its divisors is an integer number (503338908).

Almost surely, 2^2005551671 is an apocalyptic number.

2005551671 is a deficient number, since it is larger than the sum of its proper divisors (7803961).

2005551671 is an equidigital number, since it uses as much as digits as its factorization.

2005551671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7803960.

The product of its (nonzero) digits is 10500, while the sum is 32.

The square root of 2005551671 is about 44783.3861046706. The cubic root of 2005551671 is about 1261.0857507452.

The spelling of 2005551671 in words is "two billion, five million, five hundred fifty-one thousand, six hundred seventy-one".