66387517899 has 16 divisors (see below), whose sum is σ = 88814744352. Its totient is φ = 44109508608.

The previous prime is 66387517877. The next prime is 66387517913. The reversal of 66387517899 is 99871578366.

It is not a de Polignac number, because 66387517899 - 2⁸ = 66387517643 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66387517099) 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 15 ways as a sum of consecutive naturals, for example, 1421707 + ... + 1467659.

It is an arithmetic number, because the mean of its divisors is an integer number (5550921522).

Almost surely, 2^66387517899 is an apocalyptic number.

66387517899 is a deficient number, since it is larger than the sum of its proper divisors (22427226453).

66387517899 is a wasteful number, since it uses less digits than its factorization.

66387517899 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47566.

The product of its digits is 137168640, while the sum is 69.

The spelling of 66387517899 in words is "sixty-six billion, three hundred eighty-seven million, five hundred seventeen thousand, eight hundred ninety-nine".