66884855987 has 16 divisors (see below), whose sum is σ = 67660125120. Its totient is φ = 66114901632.

The previous prime is 66884855977. The next prime is 66884856023. The reversal of 66884855987 is 78955848866.

It is a cyclic number.

It is not a de Polignac number, because 66884855987 - 2⁶ = 66884855923 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66884855977) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38593973 + ... + 38595705.

It is an arithmetic number, because the mean of its divisors is an integer number (4228757820).

Almost surely, 2^66884855987 is an apocalyptic number.

66884855987 is a deficient number, since it is larger than the sum of its proper divisors (775269133).

66884855987 is a wasteful number, since it uses less digits than its factorization.

66884855987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3022.

The product of its digits is 928972800, while the sum is 74.

The spelling of 66884855987 in words is "sixty-six billion, eight hundred eighty-four million, eight hundred fifty-five thousand, nine hundred eighty-seven".