66520258560 has 1344 divisors, whose sum is σ = 292182508800. Its totient is φ = 14189395968.

The previous prime is 66520258543. The next prime is 66520258561. The reversal of 66520258560 is 6585202566.

66520258560 is a `hidden beast` number, since 6 + 6 + 5 + 2 + 0 + 2 + 585 + 60 = 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 not an unprimeable number, because it can be changed into a prime (66520258561) by changing a digit.

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 111 ways as a sum of consecutive naturals, for example, 992839647 + ... + 992839713.

It is an arithmetic number, because the mean of its divisors is an integer number (217397700).

Almost surely, 2^66520258560 is an apocalyptic number.

66520258560 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 66520258560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (146091254400).

66520258560 is an abundant number, since it is smaller than the sum of its proper divisors (225662250240).

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

66520258560 is an equidigital number, since it uses as much as digits as its factorization.

66520258560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138 (or 103 counting only the distinct ones).

The product of its (nonzero) digits is 864000, while the sum is 45.

The spelling of 66520258560 in words is "sixty-six billion, five hundred twenty million, two hundred fifty-eight thousand, five hundred sixty".