66706781547 has 32 divisors (see below), whose sum is σ = 102153445888. Its totient is φ = 37929171456.

The previous prime is 66706781539. The next prime is 66706781567. The reversal of 66706781547 is 74518760766.

It is not a de Polignac number, because 66706781547 - 2³ = 66706781539 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66706781567) 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 31 ways as a sum of consecutive naturals, for example, 4348563 + ... + 4363875.

It is an arithmetic number, because the mean of its divisors is an integer number (3192295184).

Almost surely, 2^66706781547 is an apocalyptic number.

66706781547 is a deficient number, since it is larger than the sum of its proper divisors (35446664341).

66706781547 is a wasteful number, since it uses less digits than its factorization.

66706781547 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16339.

The product of its (nonzero) digits is 11854080, while the sum is 57.

It can be divided in two parts, 66706 and 781547, that added together give a triangular number (848253 = T₁₃₀₂).

The spelling of 66706781547 in words is "sixty-six billion, seven hundred six million, seven hundred eighty-one thousand, five hundred forty-seven".