66716521287 has 16 divisors (see below), whose sum is σ = 96025654368. Its totient is φ = 40958789760.

The previous prime is 66716521279. The next prime is 66716521349. The reversal of 66716521287 is 78212561766.

It is not a de Polignac number, because 66716521287 - 2³ = 66716521279 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66716561287) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2015268 + ... + 2048105.

It is an arithmetic number, because the mean of its divisors is an integer number (6001603398).

Almost surely, 2^66716521287 is an apocalyptic number.

66716521287 is a deficient number, since it is larger than the sum of its proper divisors (29309133081).

66716521287 is a wasteful number, since it uses less digits than its factorization.

66716521287 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4063810.

The product of its digits is 1693440, while the sum is 51.

The spelling of 66716521287 in words is "sixty-six billion, seven hundred sixteen million, five hundred twenty-one thousand, two hundred eighty-seven".