66513755385 has 96 divisors (see below), whose sum is σ = 143827107840. Its totient is φ = 27625104000.

The previous prime is 66513755377. The next prime is 66513755389. The reversal of 66513755385 is 58355731566.

66513755385 is a `hidden beast` number, since 6 + 6 + 5 + 1 + 3 + 7 + 553 + 85 = 666.

It is not a de Polignac number, because 66513755385 - 2³ = 66513755377 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66513755389) 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 95 ways as a sum of consecutive naturals, for example, 6755296 + ... + 6765134.

It is an arithmetic number, because the mean of its divisors is an integer number (1498199040).

Almost surely, 2^66513755385 is an apocalyptic number.

It is an amenable number.

66513755385 is an abundant number, since it is smaller than the sum of its proper divisors (77313352455).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66513755385 is a wasteful number, since it uses less digits than its factorization.

66513755385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11819 (or 11816 counting only the distinct ones).

The product of its digits is 11340000, while the sum is 54.

The spelling of 66513755385 in words is "sixty-six billion, five hundred thirteen million, seven hundred fifty-five thousand, three hundred eighty-five".