66388306847 has 6 divisors (see below), whose sum is σ = 70066329768. Its totient is φ = 62894185092.

The previous prime is 66388306841. The next prime is 66388306879. The reversal of 66388306847 is 74860388366.

It is a happy number.

It is not a de Polignac number, because 66388306847 - 2⁸ = 66388306591 is a prime.

It is a super-2 number, since 2×66388306847² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66388306841) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 91950203 + ... + 91950924.

It is an arithmetic number, because the mean of its divisors is an integer number (11677721628).

Almost surely, 2^66388306847 is an apocalyptic number.

66388306847 is a deficient number, since it is larger than the sum of its proper divisors (3678022921).

66388306847 is a wasteful number, since it uses less digits than its factorization.

66388306847 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 183901165 (or 183901146 counting only the distinct ones).

The product of its (nonzero) digits is 27869184, while the sum is 59.

The spelling of 66388306847 in words is "sixty-six billion, three hundred eighty-eight million, three hundred six thousand, eight hundred forty-seven".