66398984145648 has 1440 divisors, whose sum is σ = 247450745138688. Its totient is φ = 16865974794240.

The previous prime is 66398984145647. The next prime is 66398984145649. The reversal of 66398984145648 is 84654148989366.

66398984145648 is a `hidden beast` number, since 6 + 6 + 3 + 9 + 8 + 9 + 8 + 41 + 4 + 564 + 8 = 666.

It is an interprime number because it is at equal distance from previous prime (66398984145647) and next prime (66398984145649).

It is a Harshad number since it is a multiple of its sum of digits (81).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66398984145647) by changing a digit.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 97216667515 + ... + 97216668197.

Almost surely, 2^{66398984145648} 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 66398984145648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (123725372569344).

66398984145648 is an abundant number, since it is smaller than the sum of its proper divisors (181051760993040).

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

66398984145648 is a wasteful number, since it uses less digits than its factorization.

66398984145648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1345 (or 1316 counting only the distinct ones).

The product of its digits is 8599633920, while the sum is 81.

The spelling of 66398984145648 in words is "sixty-six trillion, three hundred ninety-eight billion, nine hundred eighty-four million, one hundred forty-five thousand, six hundred forty-eight".