2178666886671 has 16 divisors (see below), whose sum is σ = 3521077797120. Its totient is φ = 1320404173560.

The previous prime is 2178666886657. The next prime is 2178666886687. The reversal of 2178666886671 is 1766886668712.

It is not a de Polignac number, because 2178666886671 - 2⁵ = 2178666886639 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2178666886671.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2178666886601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3667789075 + ... + 3667789668.

It is an arithmetic number, because the mean of its divisors is an integer number (220067362320).

Almost surely, 2^{2178666886671} is an apocalyptic number.

2178666886671 is a deficient number, since it is larger than the sum of its proper divisors (1342410910449).

2178666886671 is a wasteful number, since it uses less digits than its factorization.

2178666886671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7335578763 (or 7335578757 counting only the distinct ones).

The product of its digits is 390168576, while the sum is 72.

The spelling of 2178666886671 in words is "two trillion, one hundred seventy-eight billion, six hundred sixty-six million, eight hundred eighty-six thousand, six hundred seventy-one".