66860645944 has 16 divisors (see below), whose sum is σ = 126278776800. Its totient is φ = 33186305472.

The previous prime is 66860645939. The next prime is 66860645947. The reversal of 66860645944 is 44954606866.

It is a happy number.

It is a super-2 number, since 2×66860645944² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66860645947) 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 3 ways as a sum of consecutive naturals, for example, 30501024 + ... + 30503215.

It is an arithmetic number, because the mean of its divisors is an integer number (7892423550).

Almost surely, 2^66860645944 is an apocalyptic number.

It is an amenable number.

66860645944 is a deficient number, since it is larger than the sum of its proper divisors (59418130856).

66860645944 is a wasteful number, since it uses less digits than its factorization.

66860645944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61004382 (or 61004378 counting only the distinct ones).

The product of its (nonzero) digits is 29859840, while the sum is 58.

The spelling of 66860645944 in words is "sixty-six billion, eight hundred sixty million, six hundred forty-five thousand, nine hundred forty-four".