66871771 has 4 divisors (see below), whose sum is σ = 66974832. Its totient is φ = 66768712.

The previous prime is 66871759. The next prime is 66871789. The reversal of 66871771 is 17717866.

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 66871771 - 2¹¹ = 66869723 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66871711) 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 3 ways as a sum of consecutive naturals, for example, 50551 + ... + 51856.

It is an arithmetic number, because the mean of its divisors is an integer number (16743708).

Almost surely, 2^66871771 is an apocalyptic number.

66871771 is a deficient number, since it is larger than the sum of its proper divisors (103061).

66871771 is a wasteful number, since it uses less digits than its factorization.

66871771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103060.

The product of its digits is 98784, while the sum is 43.

The square root of 66871771 is about 8177.5161876942. The cubic root of 66871771 is about 405.8955359861.

The spelling of 66871771 in words is "sixty-six million, eight hundred seventy-one thousand, seven hundred seventy-one".