66724257600 has 1344 divisors, whose sum is σ = 326792417280. Its totient is φ = 12789964800.

The previous prime is 66724257569. The next prime is 66724257637. The reversal of 66724257600 is 675242766.

66724257600 is a `hidden beast` number, since 6 + 6 + 72 + 4 + 2 + 576 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1344).

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 43242429 + ... + 43243971.

It is an arithmetic number, because the mean of its divisors is an integer number (243149120).

Almost surely, 2^66724257600 is an apocalyptic number.

66724257600 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 66724257600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (163396208640).

66724257600 is an abundant number, since it is smaller than the sum of its proper divisors (260068159680).

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

66724257600 is a wasteful number, since it uses less digits than its factorization.

66724257600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1605 (or 1584 counting only the distinct ones).

The product of its (nonzero) digits is 846720, while the sum is 45.

The spelling of 66724257600 in words is "sixty-six billion, seven hundred twenty-four million, two hundred fifty-seven thousand, six hundred".