20172187055 has 4 divisors (see below), whose sum is σ = 24206624472. Its totient is φ = 16137749640.

The previous prime is 20172187039. The next prime is 20172187069. The reversal of 20172187055 is 55078127102.

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

It is not a de Polignac number, because 20172187055 - 2⁴ = 20172187039 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2017218701 + ... + 2017218710.

It is an arithmetic number, because the mean of its divisors is an integer number (6051656118).

Almost surely, 2^20172187055 is an apocalyptic number.

20172187055 is a deficient number, since it is larger than the sum of its proper divisors (4034437417).

20172187055 is an equidigital number, since it uses as much as digits as its factorization.

20172187055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4034437416.

The product of its (nonzero) digits is 39200, while the sum is 38.

The spelling of 20172187055 in words is "twenty billion, one hundred seventy-two million, one hundred eighty-seven thousand, fifty-five".