66525563520 has 1024 divisors, whose sum is σ = 269460172800. Its totient is φ = 15394406400.

The previous prime is 66525563519. The next prime is 66525563543. The reversal of 66525563520 is 2536552566.

66525563520 is a `hidden beast` number, since 6 + 6 + 5 + 2 + 5 + 5 + 635 + 2 + 0 = 666.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 285517324 + ... + 285517556.

It is an arithmetic number, because the mean of its divisors is an integer number (263144700).

Almost surely, 2^66525563520 is an apocalyptic number.

66525563520 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 66525563520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (134730086400).

66525563520 is an abundant number, since it is smaller than the sum of its proper divisors (202934609280).

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

66525563520 is a wasteful number, since it uses less digits than its factorization.

66525563520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 346 (or 328 counting only the distinct ones).

The product of its (nonzero) digits is 1620000, while the sum is 45.

The spelling of 66525563520 in words is "sixty-six billion, five hundred twenty-five million, five hundred sixty-three thousand, five hundred twenty".