66375579816 has 512 divisors, whose sum is σ = 236870860800. Its totient is φ = 16751370240.

The previous prime is 66375579763. The next prime is 66375579817. The reversal of 66375579816 is 61897557366.

66375579816 is a `hidden beast` number, since 6 + 63 + 7 + 557 + 9 + 8 + 16 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (66375579817) by changing a digit.

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, 59105031 + ... + 59106153.

It is an arithmetic number, because the mean of its divisors is an integer number (462638400).

Almost surely, 2^66375579816 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 66375579816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118435430400).

66375579816 is an abundant number, since it is smaller than the sum of its proper divisors (170495280984).

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

66375579816 is a wasteful number, since it uses less digits than its factorization.

66375579816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1286 (or 1276 counting only the distinct ones).

The product of its digits is 57153600, while the sum is 63.

The spelling of 66375579816 in words is "sixty-six billion, three hundred seventy-five million, five hundred seventy-nine thousand, eight hundred sixteen".