66615705072 has 480 divisors, whose sum is σ = 229399841280. Its totient is φ = 18354003840.

The previous prime is 66615705071. The next prime is 66615705077. The reversal of 66615705072 is 27050751666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66615705071) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 235391043 + ... + 235391325.

It is an arithmetic number, because the mean of its divisors is an integer number (477916336).

Almost surely, 2^66615705072 is an apocalyptic number.

66615705072 is a gapful number since it is divisible by the number (62) 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 66615705072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114699920640).

66615705072 is an abundant number, since it is smaller than the sum of its proper divisors (162784136208).

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

66615705072 is an equidigital number, since it uses as much as digits as its factorization.

66615705072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 381 (or 326 counting only the distinct ones).

The product of its (nonzero) digits is 529200, while the sum is 45.

The spelling of 66615705072 in words is "sixty-six billion, six hundred fifteen million, seven hundred five thousand, seventy-two".