66871885 has 4 divisors (see below), whose sum is σ = 80246268. Its totient is φ = 53497504.

The previous prime is 66871873. The next prime is 66871901. The reversal of 66871885 is 58817866.

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

It can be written as a sum of positive squares in 2 ways, for example, as 11309769 + 55562116 = 3363^2 + 7454^2 .

It is a cyclic number.

It is not a de Polignac number, because 66871885 - 2¹⁵ = 66839117 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6687184 + ... + 6687193.

It is an arithmetic number, because the mean of its divisors is an integer number (20061567).

Almost surely, 2^66871885 is an apocalyptic number.

It is an amenable number.

66871885 is a deficient number, since it is larger than the sum of its proper divisors (13374383).

66871885 is a wasteful number, since it uses less digits than its factorization.

66871885 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13374382.

The product of its digits is 645120, while the sum is 49.

The square root of 66871885 is about 8177.5231580228. The cubic root of 66871885 is about 405.8957666369.

The spelling of 66871885 in words is "sixty-six million, eight hundred seventy-one thousand, eight hundred eighty-five".