66641072656 has 20 divisors (see below), whose sum is σ = 132266276604. Its totient is φ = 32507840000.

The previous prime is 66641072623. The next prime is 66641072669. The reversal of 66641072656 is 65627014666.

It can be written as a sum of positive squares in 2 ways, for example, as 10716390400 + 55924682256 = 103520^2 + 236484^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 50792845 + ... + 50794156.

Almost surely, 2^66641072656 is an apocalyptic number.

It is an amenable number.

66641072656 is a deficient number, since it is larger than the sum of its proper divisors (65625203948).

66641072656 is a wasteful number, since it uses less digits than its factorization.

66641072656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101587050 (or 101587044 counting only the distinct ones).

The product of its (nonzero) digits is 2177280, while the sum is 49.

The spelling of 66641072656 in words is "sixty-six billion, six hundred forty-one million, seventy-two thousand, six hundred fifty-six".