66438847084787 has 4 divisors (see below), whose sum is σ = 66465669391296. Its totient is φ = 66412024778280.

The previous prime is 66438847084777. The next prime is 66438847084789. The reversal of 66438847084787 is 78748074883466.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66438847084787 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66438847084789) 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 3 ways as a sum of consecutive naturals, for example, 13411149539 + ... + 13411154492.

It is an arithmetic number, because the mean of its divisors is an integer number (16616417347824).

Almost surely, 2^{66438847084787} is an apocalyptic number.

66438847084787 is a deficient number, since it is larger than the sum of its proper divisors (26822306509).

66438847084787 is a wasteful number, since it uses less digits than its factorization.

66438847084787 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26822306508.

The product of its (nonzero) digits is 9710862336, while the sum is 80.

The spelling of 66438847084787 in words is "sixty-six trillion, four hundred thirty-eight billion, eight hundred forty-seven million, eighty-four thousand, seven hundred eighty-seven".