66828644642 has 8 divisors (see below), whose sum is σ = 100460415132. Its totient is φ = 33341839600.

The previous prime is 66828644639. The next prime is 66828644647. The reversal of 66828644642 is 24644682866.

It can be written as a sum of positive squares in 2 ways, for example, as 66821733001 + 6911641 = 258499^2 + 2629^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (66828644647) 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 3 ways as a sum of consecutive naturals, for example, 36240209 + ... + 36242052.

Almost surely, 2^66828644642 is an apocalyptic number.

66828644642 is a deficient number, since it is larger than the sum of its proper divisors (33631770490).

66828644642 is a wasteful number, since it uses less digits than its factorization.

66828644642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72482724.

The product of its digits is 21233664, while the sum is 56.

The spelling of 66828644642 in words is "sixty-six billion, eight hundred twenty-eight million, six hundred forty-four thousand, six hundred forty-two".