66173987827 has 4 divisors (see below), whose sum is σ = 66219975360. Its totient is φ = 66128000296.

The previous prime is 66173987819. The next prime is 66173987881. The reversal of 66173987827 is 72878937166.

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

It is a cyclic number.

It is not a de Polignac number, because 66173987827 - 2³ = 66173987819 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66173987927) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22991608 + ... + 22994485.

It is an arithmetic number, because the mean of its divisors is an integer number (16554993840).

Almost surely, 2^66173987827 is an apocalyptic number.

66173987827 is a deficient number, since it is larger than the sum of its proper divisors (45987533).

66173987827 is a wasteful number, since it uses less digits than its factorization.

66173987827 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45987532.

The product of its digits is 42674688, while the sum is 64.

The spelling of 66173987827 in words is "sixty-six billion, one hundred seventy-three million, nine hundred eighty-seven thousand, eight hundred twenty-seven".