66143645221205 has 4 divisors (see below), whose sum is σ = 79372374265452. Its totient is φ = 52914916176960.

The previous prime is 66143645221189. The next prime is 66143645221211. The reversal of 66143645221205 is 50212254634166.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 22612060185796 + 43531585035409 = 4755214^2 + 6597847^2 .

It is not a de Polignac number, because 66143645221205 - 2⁴ = 66143645221189 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66143645221205.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 6614364522116 + ... + 6614364522125.

It is an arithmetic number, because the mean of its divisors is an integer number (19843093566363).

Almost surely, 2^{66143645221205} is an apocalyptic number.

It is an amenable number.

66143645221205 is a deficient number, since it is larger than the sum of its proper divisors (13228729044247).

66143645221205 is a wasteful number, since it uses less digits than its factorization.

66143645221205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13228729044246.

The product of its (nonzero) digits is 2073600, while the sum is 47.

The spelling of 66143645221205 in words is "sixty-six trillion, one hundred forty-three billion, six hundred forty-five million, two hundred twenty-one thousand, two hundred five".