66678696854417 has 16 divisors (see below), whose sum is σ = 71977667402880. Its totient is φ = 61579758240000.

The previous prime is 66678696854389. The next prime is 66678696854443. The reversal of 66678696854417 is 71445869687666.

It is a cyclic number.

It is not a de Polignac number, because 66678696854417 - 2²² = 66678692660113 is a prime.

It is a super-2 number, since 2×66678696854417² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66678696854447) 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 15 ways as a sum of consecutive naturals, for example, 83411417 + ... + 84207017.

It is an arithmetic number, because the mean of its divisors is an integer number (4498604212680).

Almost surely, 2^{66678696854417} is an apocalyptic number.

It is an amenable number.

66678696854417 is a deficient number, since it is larger than the sum of its proper divisors (5298970548463).

66678696854417 is a wasteful number, since it uses less digits than its factorization.

66678696854417 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 921304.

The product of its digits is 17557585920, while the sum is 83.

The spelling of 66678696854417 in words is "sixty-six trillion, six hundred seventy-eight billion, six hundred ninety-six million, eight hundred fifty-four thousand, four hundred seventeen".