66721740207300 has 216 divisors, whose sum is σ = 209634053265000. Its totient is φ = 17750069084160.

The previous prime is 66721740207289. The next prime is 66721740207371. The reversal of 66721740207300 is 370204712766.

66721740207300 is a `hidden beast` number, since 6 + 6 + 72 + 1 + 74 + 0 + 207 + 300 = 666.

It can be written as a sum of positive squares in 12 ways, for example, as 48215775162564 + 18505965044736 = 6943758^2 + 4301856^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 4888390876 + ... + 4888404524.

It is an arithmetic number, because the mean of its divisors is an integer number (970528024375).

Almost surely, 2^{66721740207300} is an apocalyptic number.

66721740207300 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 66721740207300, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (104817026632500).

66721740207300 is an abundant number, since it is smaller than the sum of its proper divisors (142912313057700).

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

66721740207300 is a wasteful number, since it uses less digits than its factorization.

66721740207300 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26215 (or 26205 counting only the distinct ones).

The product of its (nonzero) digits is 592704, while the sum is 45.

The spelling of 66721740207300 in words is "sixty-six trillion, seven hundred twenty-one billion, seven hundred forty million, two hundred seven thousand, three hundred".