66185138880 has 1260 divisors, whose sum is σ = 289768019904. Its totient is φ = 14282956800.

The previous prime is 66185138863. The next prime is 66185138893. The reversal of 66185138880 is 8883158166.

66185138880 is a `hidden beast` number, since 6 + 6 + 185 + 1 + 388 + 80 = 666.

It is a tau number, because it is divible by the number of its divisors (1260).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 179 ways as a sum of consecutive naturals, for example, 1614271660 + ... + 1614271700.

Almost surely, 2^66185138880 is an apocalyptic number.

66185138880 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66185138880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (144884009952).

66185138880 is an abundant number, since it is smaller than the sum of its proper divisors (223582881024).

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

66185138880 is a wasteful number, since it uses less digits than its factorization.

66185138880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156 (or 89 counting only the distinct ones).

The product of its (nonzero) digits is 2211840, while the sum is 54.

The spelling of 66185138880 in words is "sixty-six billion, one hundred eighty-five million, one hundred thirty-eight thousand, eight hundred eighty".