66814788513 has 16 divisors (see below), whose sum is σ = 99445268736. Its totient is φ = 39552093840.

The previous prime is 66814788487. The next prime is 66814788533. The reversal of 66814788513 is 31588741866.

It is a happy number.

It is not a de Polignac number, because 66814788513 - 2⁶ = 66814788449 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66814788533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23541495 + ... + 23544332.

It is an arithmetic number, because the mean of its divisors is an integer number (6215329296).

Almost surely, 2^66814788513 is an apocalyptic number.

It is an amenable number.

66814788513 is a deficient number, since it is larger than the sum of its proper divisors (32630480223).

66814788513 is a wasteful number, since it uses less digits than its factorization.

66814788513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47085884.

The product of its digits is 7741440, while the sum is 57.

The spelling of 66814788513 in words is "sixty-six billion, eight hundred fourteen million, seven hundred eighty-eight thousand, five hundred thirteen".