6561001500505 has 4 divisors (see below), whose sum is σ = 7873201800612. Its totient is φ = 5248801200400.

The previous prime is 6561001500497. The next prime is 6561001500509. The reversal of 6561001500505 is 5050051001656.

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 899380999449 + 5661620501056 = 948357^2 + 2379416^2 .

It is not a de Polignac number, because 6561001500505 - 2³ = 6561001500497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6561001500509) 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, 656100150046 + ... + 656100150055.

It is an arithmetic number, because the mean of its divisors is an integer number (1968300450153).

Almost surely, 2^{6561001500505} is an apocalyptic number.

It is an amenable number.

6561001500505 is a deficient number, since it is larger than the sum of its proper divisors (1312200300107).

6561001500505 is a wasteful number, since it uses less digits than its factorization.

6561001500505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1312200300106.

The product of its (nonzero) digits is 22500, while the sum is 34.

The spelling of 6561001500505 in words is "six trillion, five hundred sixty-one billion, one million, five hundred thousand, five hundred five".