1205536666 has 4 divisors (see below), whose sum is σ = 1808305002. Its totient is φ = 602768332.

The previous prime is 1205536639. The next prime is 1205536669. The reversal of 1205536666 is 6666355021.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6666355021 = 1429 ⋅4665049.

It can be written as a sum of positive squares in only one way, i.e., 1195430625 + 10106041 = 34575^2 + 3179^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (1205536669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 301384165 + ... + 301384168.

Almost surely, 2^1205536666 is an apocalyptic number.

1205536666 is a deficient number, since it is larger than the sum of its proper divisors (602768336).

1205536666 is an equidigital number, since it uses as much as digits as its factorization.

1205536666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 602768335.

The product of its (nonzero) digits is 194400, while the sum is 40.

The square root of 1205536666 is about 34720.8390739625. The cubic root of 1205536666 is about 1064.2903913930.

The spelling of 1205536666 in words is "one billion, two hundred five million, five hundred thirty-six thousand, six hundred sixty-six".