66771118765 has 32 divisors (see below), whose sum is σ = 87514721280. Its totient is φ = 48609310464.

The previous prime is 66771118751. The next prime is 66771118769. The reversal of 66771118765 is 56781117766.

It is not a de Polignac number, because 66771118765 - 2¹¹ = 66771116717 is a prime.

It is a super-2 number, since 2×66771118765² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66771118769) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3466792 + ... + 3485998.

It is an arithmetic number, because the mean of its divisors is an integer number (2734835040).

Almost surely, 2^66771118765 is an apocalyptic number.

66771118765 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

66771118765 is a deficient number, since it is larger than the sum of its proper divisors (20743602515).

66771118765 is a wasteful number, since it uses less digits than its factorization.

66771118765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19981.

The product of its digits is 2963520, while the sum is 55.

Subtracting from 66771118765 its reverse (56781117766), we obtain a palindrome (9990000999).

The spelling of 66771118765 in words is "sixty-six billion, seven hundred seventy-one million, one hundred eighteen thousand, seven hundred sixty-five".