1605236605663 has 4 divisors (see below), whose sum is σ = 1605687898680. Its totient is φ = 1604785312648.

The previous prime is 1605236605601. The next prime is 1605236605681. The reversal of 1605236605663 is 3665066325061.

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

It is a cyclic number.

It is not a de Polignac number, because 1605236605663 - 2⁹ = 1605236605151 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1605236602663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 225641173 + ... + 225648286.

It is an arithmetic number, because the mean of its divisors is an integer number (401421974670).

Almost surely, 2^{1605236605663} is an apocalyptic number.

1605236605663 is a deficient number, since it is larger than the sum of its proper divisors (451293017).

1605236605663 is an equidigital number, since it uses as much as digits as its factorization.

1605236605663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 451293016.

The product of its (nonzero) digits is 3499200, while the sum is 49.

The spelling of 1605236605663 in words is "one trillion, six hundred five billion, two hundred thirty-six million, six hundred five thousand, six hundred sixty-three".