66871811 has 4 divisors (see below), whose sum is σ = 70391400. Its totient is φ = 63352224.

The previous prime is 66871801. The next prime is 66871843. The reversal of 66871811 is 11817866.

66871811 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11817866 = 2 ⋅5908933.

It is a cyclic number.

It is not a de Polignac number, because 66871811 - 2⁶ = 66871747 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66871801) 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, 1759766 + ... + 1759803.

It is an arithmetic number, because the mean of its divisors is an integer number (17597850).

Almost surely, 2^66871811 is an apocalyptic number.

66871811 is a deficient number, since it is larger than the sum of its proper divisors (3519589).

66871811 is a wasteful number, since it uses less digits than its factorization.

66871811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3519588.

The product of its digits is 16128, while the sum is 38.

The square root of 66871811 is about 8177.5186334242. The cubic root of 66871811 is about 405.8956169162.

The spelling of 66871811 in words is "sixty-six million, eight hundred seventy-one thousand, eight hundred eleven".