66815761728403 has 16 divisors (see below), whose sum is σ = 72227475361440. Its totient is φ = 61601257728000.

The previous prime is 66815761728389. The next prime is 66815761728407. The reversal of 66815761728403 is 30482716751866.

66815761728403 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66815761728403 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66815761728407) 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 15 ways as a sum of consecutive naturals, for example, 106634250 + ... + 107259007.

It is an arithmetic number, because the mean of its divisors is an integer number (4514217210090).

Almost surely, 2^{66815761728403} is an apocalyptic number.

66815761728403 is a deficient number, since it is larger than the sum of its proper divisors (5411713633037).

66815761728403 is a wasteful number, since it uses less digits than its factorization.

66815761728403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213893718.

The product of its (nonzero) digits is 81285120, while the sum is 64.

The spelling of 66815761728403 in words is "sixty-six trillion, eight hundred fifteen billion, seven hundred sixty-one million, seven hundred twenty-eight thousand, four hundred three".