66778981140 has 24 divisors (see below), whose sum is σ = 186981147360. Its totient is φ = 17807728288.

The previous prime is 66778981109. The next prime is 66778981141. The reversal of 66778981140 is 4118987766.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66778981141) 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 7 ways as a sum of consecutive naturals, for example, 556491450 + ... + 556491569.

It is an arithmetic number, because the mean of its divisors is an integer number (7790881140).

Almost surely, 2^66778981140 is an apocalyptic number.

66778981140 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66778981140 is an abundant number, since it is smaller than the sum of its proper divisors (120202166220).

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

66778981140 is a wasteful number, since it uses less digits than its factorization.

66778981140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1112983031 (or 1112983029 counting only the distinct ones).

The product of its (nonzero) digits is 4064256, while the sum is 57.

The spelling of 66778981140 in words is "sixty-six billion, seven hundred seventy-eight million, nine hundred eighty-one thousand, one hundred forty".