66871856 has 20 divisors (see below), whose sum is σ = 135198192. Its totient is φ = 31982016.

The previous prime is 66871843. The next prime is 66871859. The reversal of 66871856 is 65817866.

66871856 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 66871856.

It is not an unprimeable number, because it can be changed into a prime (66871859) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 90491 + ... + 91226.

Almost surely, 2^66871856 is an apocalyptic number.

It is an amenable number.

66871856 is an abundant number, since it is smaller than the sum of its proper divisors (68326336).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66871856 is a wasteful number, since it uses less digits than its factorization.

66871856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 181748 (or 181742 counting only the distinct ones).

The product of its digits is 483840, while the sum is 47.

The square root of 66871856 is about 8177.5213848696. The cubic root of 66871856 is about 405.8957079626.

The spelling of 66871856 in words is "sixty-six million, eight hundred seventy-one thousand, eight hundred fifty-six".