66776568871 has 4 divisors (see below), whose sum is σ = 70704602352. Its totient is φ = 62848535392.

The previous prime is 66776568853. The next prime is 66776568913. The reversal of 66776568871 is 17886567766.

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 66776568871 - 2⁷ = 66776568743 is a prime.

It is a super-2 number, since 2×66776568871² (a number of 22 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 66776568797 and 66776568806.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66776568811) 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, 1964016715 + ... + 1964016748.

It is an arithmetic number, because the mean of its divisors is an integer number (17676150588).

Almost surely, 2^66776568871 is an apocalyptic number.

66776568871 is a deficient number, since it is larger than the sum of its proper divisors (3928033481).

66776568871 is a wasteful number, since it uses less digits than its factorization.

66776568871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3928033480.

The product of its digits is 142248960, while the sum is 67.

The spelling of 66776568871 in words is "sixty-six billion, seven hundred seventy-six million, five hundred sixty-eight thousand, eight hundred seventy-one".