66640720330000 has 50 divisors (see below), whose sum is σ = 161343848015174. Its totient is φ = 26656288128000.

The previous prime is 66640720329979. The next prime is 66640720330043. The reversal of 66640720330000 is 3302704666.

It can be written as a sum of positive squares in 5 ways, for example, as 10157198465296 + 56483521864704 = 3187036^2 + 7515552^2 .

It is a tau number, because it is divible by the number of its divisors (50).

It is a super-2 number, since 2×66640720330000² (a number of 28 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 3332026017 + ... + 3332046016.

Almost surely, 2^{66640720330000} is an apocalyptic number.

It is an amenable number.

66640720330000 is an abundant number, since it is smaller than the sum of its proper divisors (94703127685174).

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

66640720330000 is an equidigital number, since it uses as much as digits as its factorization.

66640720330000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6664072061 (or 6664072040 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 37.

The spelling of 66640720330000 in words is "sixty-six trillion, six hundred forty billion, seven hundred twenty million, three hundred thirty thousand".