66816578180 has 48 divisors (see below), whose sum is σ = 153182885184. Its totient is φ = 24279131520.

The previous prime is 66816578077. The next prime is 66816578183. The reversal of 66816578180 is 8187561866.

It is a happy number.

It is a super-2 number, since 2×66816578180² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66816578183) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 191459 + ... + 412661.

It is an arithmetic number, because the mean of its divisors is an integer number (3191310108).

Almost surely, 2^66816578180 is an apocalyptic number.

It is an amenable number.

66816578180 is an abundant number, since it is smaller than the sum of its proper divisors (86366307004).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66816578180 is a wasteful number, since it uses less digits than its factorization.

66816578180 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 222596 (or 222594 counting only the distinct ones).

The product of its (nonzero) digits is 3870720, while the sum is 56.

The spelling of 66816578180 in words is "sixty-six billion, eight hundred sixteen million, five hundred seventy-eight thousand, one hundred eighty".