2005555621 has 16 divisors (see below), whose sum is σ = 2153810560. Its totient is φ = 1861807680.

The previous prime is 2005555619. The next prime is 2005555649. The reversal of 2005555621 is 1265555002.

It is a cyclic number.

It is not a de Polignac number, because 2005555621 - 2¹ = 2005555619 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 (2005555661) 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, 317920 + ... + 324166.

It is an arithmetic number, because the mean of its divisors is an integer number (134613160).

Almost surely, 2^2005555621 is an apocalyptic number.

It is an amenable number.

2005555621 is a deficient number, since it is larger than the sum of its proper divisors (148254939).

2005555621 is a wasteful number, since it uses less digits than its factorization.

2005555621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6604.

The product of its (nonzero) digits is 15000, while the sum is 31.

The square root of 2005555621 is about 44783.4302058250. The cubic root of 2005555621 is about 1261.0865786613.

The spelling of 2005555621 in words is "two billion, five million, five hundred fifty-five thousand, six hundred twenty-one".