66535813887 has 16 divisors (see below), whose sum is σ = 93705858048. Its totient is φ = 41928042240.

The previous prime is 66535813793. The next prime is 66535813891. The reversal of 66535813887 is 78831853566.

It is not a de Polignac number, because 66535813887 - 2¹⁵ = 66535781119 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66535813887.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66535813187) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8315058 + ... + 8323055.

It is an arithmetic number, because the mean of its divisors is an integer number (5856616128).

Almost surely, 2^66535813887 is an apocalyptic number.

66535813887 is a deficient number, since it is larger than the sum of its proper divisors (27170044161).

66535813887 is a wasteful number, since it uses less digits than its factorization.

66535813887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16638190.

The product of its digits is 29030400, while the sum is 60.

The spelling of 66535813887 in words is "sixty-six billion, five hundred thirty-five million, eight hundred thirteen thousand, eight hundred eighty-seven".