66688822778887 has 8 divisors (see below), whose sum is σ = 67614816197600. Its totient is φ = 65763165790080.

The previous prime is 66688822778843. The next prime is 66688822778947. The reversal of 66688822778887 is 78887722888666.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66688822778887 - 2⁷ = 66688822778759 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 (66688822778827) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 83708262 + ... + 84501187.

It is an arithmetic number, because the mean of its divisors is an integer number (8451852024700).

Almost surely, 2^{66688822778887} is an apocalyptic number.

66688822778887 is a deficient number, since it is larger than the sum of its proper divisors (925993418713).

66688822778887 is a wasteful number, since it uses less digits than its factorization.

66688822778887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168214953.

The product of its digits is 77686898688, while the sum is 91.

The spelling of 66688822778887 in words is "sixty-six trillion, six hundred eighty-eight billion, eight hundred twenty-two million, seven hundred seventy-eight thousand, eight hundred eighty-seven".