66255065856 has 504 divisors, whose sum is σ = 232327695264. Its totient is φ = 18453381120.

The previous prime is 66255065837. The next prime is 66255065857. The reversal of 66255065856 is 65856055266.

66255065856 is a `hidden beast` number, since 6 + 6 + 2 + 5 + 50 + 6 + 585 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (504).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (66255065857) by changing a digit.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 53560470 + ... + 53561706.

Almost surely, 2^66255065856 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66255065856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116163847632).

66255065856 is an abundant number, since it is smaller than the sum of its proper divisors (166072629408).

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

66255065856 is an equidigital number, since it uses as much as digits as its factorization.

66255065856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1319 (or 1290 counting only the distinct ones).

The product of its (nonzero) digits is 12960000, while the sum is 54.

The spelling of 66255065856 in words is "sixty-six billion, two hundred fifty-five million, sixty-five thousand, eight hundred fifty-six".