66808255171 has 36 divisors (see below), whose sum is σ = 83363456232. Its totient is φ = 53192221824.

The previous prime is 66808255169. The next prime is 66808255177. The reversal of 66808255171 is 17155280866.

It is not a de Polignac number, because 66808255171 - 2¹ = 66808255169 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66808255177) 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 35 ways as a sum of consecutive naturals, for example, 67963146 + ... + 67964128.

It is an arithmetic number, because the mean of its divisors is an integer number (2315651562).

Almost surely, 2^66808255171 is an apocalyptic number.

66808255171 is a deficient number, since it is larger than the sum of its proper divisors (16555201061).

66808255171 is an frugal number, since it uses more digits than its factorization.

66808255171 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2080 (or 1090 counting only the distinct ones).

The product of its (nonzero) digits is 806400, while the sum is 49.

The spelling of 66808255171 in words is "sixty-six billion, eight hundred eight million, two hundred fifty-five thousand, one hundred seventy-one".