66438847084788 has 36 divisors (see below), whose sum is σ = 167987630234788. Its totient is φ = 22140349747200.

The previous prime is 66438847084777. The next prime is 66438847084789. The reversal of 66438847084788 is 88748074883466.

66438847084788 is a `hidden beast` number, since 6 + 64 + 3 + 8 + 8 + 470 + 8 + 4 + 7 + 88 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 47294476901604 + 19144370183184 = 6877098^2 + 4375428^2 .

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

It is a super-2 number, since 2×66438847084788² (a number of 28 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66438847084789) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 247056013 + ... + 247324788.

Almost surely, 2^{66438847084788} is an apocalyptic number.

It is an amenable number.

66438847084788 is an abundant number, since it is smaller than the sum of its proper divisors (101548783150000).

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

66438847084788 is a wasteful number, since it uses less digits than its factorization.

66438847084788 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 494384544 (or 494384539 counting only the distinct ones).

The product of its (nonzero) digits is 11098128384, while the sum is 81.

The spelling of 66438847084788 in words is "sixty-six trillion, four hundred thirty-eight billion, eight hundred forty-seven million, eighty-four thousand, seven hundred eighty-eight".