2001405555 has 48 divisors (see below), whose sum is σ = 3507888384. Its totient is φ = 1055545920.

The previous prime is 2001405551. The next prime is 2001405569. The reversal of 2001405555 is 5555041002.

2001405555 is a `hidden beast` number, since 200 + 1 + 405 + 5 + 55 = 666.

It is not a de Polignac number, because 2001405555 - 2² = 2001405551 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2001405551) 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 47 ways as a sum of consecutive naturals, for example, 2752602 + ... + 2753328.

It is an arithmetic number, because the mean of its divisors is an integer number (73081008).

Almost surely, 2^2001405555 is an apocalyptic number.

2001405555 is a deficient number, since it is larger than the sum of its proper divisors (1506482829).

2001405555 is a wasteful number, since it uses less digits than its factorization.

2001405555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1336 (or 1333 counting only the distinct ones).

The product of its (nonzero) digits is 5000, while the sum is 27.

The square root of 2001405555 is about 44737.0713726323. The cubic root of 2001405555 is about 1260.2161288359.

Adding to 2001405555 its reverse (5555041002), we get a palindrome (7556446557).

The spelling of 2001405555 in words is "two billion, one million, four hundred five thousand, five hundred fifty-five".