66063728640 has 768 divisors, whose sum is σ = 266086779840. Its totient is φ = 13872660480.

The previous prime is 66063728639. The next prime is 66063728663. The reversal of 66063728640 is 4682736066.

It is a tau number, because it is divible by the number of its divisors (768).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 66063728640.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 313098135 + ... + 313098345.

Almost surely, 2^66063728640 is an apocalyptic number.

66063728640 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 66063728640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133043389920).

66063728640 is an abundant number, since it is smaller than the sum of its proper divisors (200023051200).

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

66063728640 is a wasteful number, since it uses less digits than its factorization.

66063728640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 276 (or 241 counting only the distinct ones).

The product of its (nonzero) digits is 1741824, while the sum is 48.

The spelling of 66063728640 in words is "sixty-six billion, sixty-three million, seven hundred twenty-eight thousand, six hundred forty".