66640720329999 has 32 divisors (see below), whose sum is σ = 100118966592000. Its totient is φ = 43801239810240.

The previous prime is 66640720329979. The next prime is 66640720330043. The reversal of 66640720329999 is 99992302704666.

66640720329999 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 66640720329999 - 2¹⁹ = 66640719805711 is a prime.

It is a super-2 number, since 2×66640720329999² (a number of 28 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66640720329929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1690699 + ... + 11667900.

It is an arithmetic number, because the mean of its divisors is an integer number (3128717706000).

Almost surely, 2^{66640720329999} is an apocalyptic number.

66640720329999 is a deficient number, since it is larger than the sum of its proper divisors (33478246262001).

66640720329999 is a wasteful number, since it uses less digits than its factorization.

66640720329999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13361212 (or 13361206 counting only the distinct ones).

The product of its (nonzero) digits is 476171136, while the sum is 72.

The spelling of 66640720329999 in words is "sixty-six trillion, six hundred forty billion, seven hundred twenty million, three hundred twenty-nine thousand, nine hundred ninety-nine".