1205541641666 has 4 divisors (see below), whose sum is σ = 1808312462502. Its totient is φ = 602770820832.

The previous prime is 1205541641569. The next prime is 1205541641669. The reversal of 1205541641666 is 6661461455021.

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

It can be written as a sum of positive squares in only one way, i.e., 1030925469025 + 174616172641 = 1015345^2 + 417871^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1205541641666.

It is not an unprimeable number, because it can be changed into a prime (1205541641669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 301385410415 + ... + 301385410418.

Almost surely, 2^{1205541641666} is an apocalyptic number.

1205541641666 is a deficient number, since it is larger than the sum of its proper divisors (602770820836).

1205541641666 is an equidigital number, since it uses as much as digits as its factorization.

1205541641666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 602770820835.

The product of its (nonzero) digits is 1036800, while the sum is 47.

The spelling of 1205541641666 in words is "one trillion, two hundred five billion, five hundred forty-one million, six hundred forty-one thousand, six hundred sixty-six".