66215268864 has 120 divisors (see below), whose sum is σ = 192958489152. Its totient is φ = 21857310720.

The previous prime is 66215268851. The next prime is 66215268877. The reversal of 66215268864 is 46886251266.

66215268864 is a `hidden beast` number, since 6 + 621 + 5 + 2 + 6 + 8 + 8 + 6 + 4 = 666.

It is an interprime number because it is at equal distance from previous prime (66215268851) and next prime (66215268877).

It is a self number, because there is not a number n which added to its sum of digits gives 66215268864.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 404869 + ... + 544379.

Almost surely, 2^66215268864 is an apocalyptic number.

66215268864 is a gapful number since it is divisible by the number (64) 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 66215268864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96479244576).

66215268864 is an abundant number, since it is smaller than the sum of its proper divisors (126743220288).

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

66215268864 is a wasteful number, since it uses less digits than its factorization.

66215268864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139638 (or 139619 counting only the distinct ones).

The product of its digits is 6635520, while the sum is 54.

The spelling of 66215268864 in words is "sixty-six billion, two hundred fifteen million, two hundred sixty-eight thousand, eight hundred sixty-four".