66187447 has 4 divisors (see below), whose sum is σ = 66708736. Its totient is φ = 65666160.

The previous prime is 66187411. The next prime is 66187463. The reversal of 66187447 is 74478166.

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 66187447 - 2¹⁹ = 65663159 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66137447) 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, 260454 + ... + 260707.

It is an arithmetic number, because the mean of its divisors is an integer number (16677184).

Almost surely, 2^66187447 is an apocalyptic number.

66187447 is a deficient number, since it is larger than the sum of its proper divisors (521289).

66187447 is a wasteful number, since it uses less digits than its factorization.

66187447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 521288.

The product of its digits is 225792, while the sum is 43.

The square root of 66187447 is about 8135.5667903349. The cubic root of 66187447 is about 404.5062254478.

The spelling of 66187447 in words is "sixty-six million, one hundred eighty-seven thousand, four hundred forty-seven".