20021668555 has 16 divisors (see below), whose sum is σ = 27469301184. Its totient is φ = 13723637760.

The previous prime is 20021668547. The next prime is 20021668561. The reversal of 20021668555 is 55586612002.

It is not a de Polignac number, because 20021668555 - 2³ = 20021668547 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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, 25222 + ... + 201691.

It is an arithmetic number, because the mean of its divisors is an integer number (1716831324).

Almost surely, 2^20021668555 is an apocalyptic number.

20021668555 is a deficient number, since it is larger than the sum of its proper divisors (7447632629).

20021668555 is a wasteful number, since it uses less digits than its factorization.

20021668555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 229446.

The product of its (nonzero) digits is 144000, while the sum is 40.

The spelling of 20021668555 in words is "twenty billion, twenty-one million, six hundred sixty-eight thousand, five hundred fifty-five".