66667918786560 has 2880 divisors, whose sum is σ = 302934061406592. Its totient is φ = 13649338957824.

The previous prime is 66667918786543. The next prime is 66667918786583. The reversal of 66667918786560 is 6568781976666.

It is a tau number, because it is divible by the number of its divisors (2880).

It is a super-2 number, since 2×66667918786560² (a number of 28 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (81).

It is a self number, because there is not a number n which added to its sum of digits gives 66667918786560.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 178734366534 + ... + 178734366906.

Almost surely, 2^{66667918786560} is an apocalyptic number.

66667918786560 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 66667918786560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (151467030703296).

66667918786560 is an abundant number, since it is smaller than the sum of its proper divisors (236266142620032).

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

66667918786560 is an equidigital number, since it uses as much as digits as its factorization.

66667918786560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 481 (or 440 counting only the distinct ones).

The product of its (nonzero) digits is 6584094720, while the sum is 81.

The spelling of 66667918786560 in words is "sixty-six trillion, six hundred sixty-seven billion, nine hundred eighteen million, seven hundred eighty-six thousand, five hundred sixty".