66213826560 has 1248 divisors, whose sum is σ = 287452988160. Its totient is φ = 13759414272.

The previous prime is 66213826517. The next prime is 66213826577. The reversal of 66213826560 is 6562831266.

66213826560 is a `hidden beast` number, since 6 + 6 + 2 + 1 + 3 + 82 + 6 + 560 = 666.

It is a super-2 number, since 2×66213826560² (a number of 22 digits) contains 22 as substring.

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 polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 907038684 + ... + 907038756.

It is an arithmetic number, because the mean of its divisors is an integer number (230330920).

Almost surely, 2^66213826560 is an apocalyptic number.

66213826560 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 66213826560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (143726494080).

66213826560 is an abundant number, since it is smaller than the sum of its proper divisors (221239161600).

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

66213826560 is a wasteful number, since it uses less digits than its factorization.

66213826560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171 (or 146 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 45.

The spelling of 66213826560 in words is "sixty-six billion, two hundred thirteen million, eight hundred twenty-six thousand, five hundred sixty".