66665511000640 has 224 divisors, whose sum is σ = 166032021991680. Its totient is φ = 25463446020096.

The previous prime is 66665511000577. The next prime is 66665511000707. The reversal of 66665511000640 is 4600011556666.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 738819207 + ... + 738909433.

Almost surely, 2^{66665511000640} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66665511000640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (83016010995840).

66665511000640 is an abundant number, since it is smaller than the sum of its proper divisors (99366510991040).

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

66665511000640 is a wasteful number, since it uses less digits than its factorization.

66665511000640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91149 (or 91139 counting only the distinct ones).

The product of its (nonzero) digits is 777600, while the sum is 46.

The spelling of 66665511000640 in words is "sixty-six trillion, six hundred sixty-five billion, five hundred eleven million, six hundred forty", and thus it is an aban number.