2605163304721 has 4 divisors (see below), whose sum is σ = 2605522992112. Its totient is φ = 2604803617332.

The previous prime is 2605163304677. The next prime is 2605163304749. The reversal of 2605163304721 is 1274033615062.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2605163304721 - 2⁹ = 2605163304209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2605863304721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 179832831 + ... + 179847316.

It is an arithmetic number, because the mean of its divisors is an integer number (651380748028).

Almost surely, 2^{2605163304721} is an apocalyptic number.

It is an amenable number.

2605163304721 is a deficient number, since it is larger than the sum of its proper divisors (359687391).

2605163304721 is an equidigital number, since it uses as much as digits as its factorization.

2605163304721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 359687390.

The product of its (nonzero) digits is 181440, while the sum is 40.

Adding to 2605163304721 its reverse (1274033615062), we get a palindrome (3879196919783).

The spelling of 2605163304721 in words is "two trillion, six hundred five billion, one hundred sixty-three million, three hundred four thousand, seven hundred twenty-one".