66505131612 has 36 divisors (see below), whose sum is σ = 171282089160. Its totient is φ = 21750105312.

The previous prime is 66505131587. The next prime is 66505131613. The reversal of 66505131612 is 21613150566.

66505131612 is a `hidden beast` number, since 6 + 6 + 5 + 0 + 5 + 1 + 31 + 612 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66505131613) 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 11 ways as a sum of consecutive naturals, for example, 17426062 + ... + 17429877.

It is an arithmetic number, because the mean of its divisors is an integer number (4757835810).

Almost surely, 2^66505131612 is an apocalyptic number.

It is an amenable number.

66505131612 is an abundant number, since it is smaller than the sum of its proper divisors (104776957548).

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

66505131612 is a wasteful number, since it uses less digits than its factorization.

66505131612 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34856002 (or 34855997 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

The spelling of 66505131612 in words is "sixty-six billion, five hundred five million, one hundred thirty-one thousand, six hundred twelve".