6561506160505 has 4 divisors (see below), whose sum is σ = 7873807392612. Its totient is φ = 5249204928400.

The previous prime is 6561506160427. The next prime is 6561506160529. The reversal of 6561506160505 is 5050616051656.

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 1204262617321 + 5357243543184 = 1097389^2 + 2314572^2 .

It is not a de Polignac number, because 6561506160505 - 2⁹ = 6561506159993 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 656150616046 + ... + 656150616055.

It is an arithmetic number, because the mean of its divisors is an integer number (1968451848153).

Almost surely, 2^{6561506160505} is an apocalyptic number.

It is an amenable number.

6561506160505 is a deficient number, since it is larger than the sum of its proper divisors (1312301232107).

6561506160505 is a wasteful number, since it uses less digits than its factorization.

6561506160505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1312301232106.

The product of its (nonzero) digits is 810000, while the sum is 46.

The spelling of 6561506160505 in words is "six trillion, five hundred sixty-one billion, five hundred six million, one hundred sixty thousand, five hundred five".