6561161223 has 4 divisors (see below), whose sum is σ = 8748214968. Its totient is φ = 4374107480.

The previous prime is 6561161213. The next prime is 6561161251. The reversal of 6561161223 is 3221611656.

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 6561161223 - 2⁴ = 6561161207 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6561161213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1093526868 + ... + 1093526873.

It is an arithmetic number, because the mean of its divisors is an integer number (2187053742).

Almost surely, 2^6561161223 is an apocalyptic number.

6561161223 is a deficient number, since it is larger than the sum of its proper divisors (2187053745).

6561161223 is a wasteful number, since it uses less digits than its factorization.

6561161223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2187053744.

The product of its digits is 12960, while the sum is 33.

The square root of 6561161223 is about 81000.9951975900. The cubic root of 6561161223 is about 1872.0907747480.

Adding to 6561161223 its reverse (3221611656), we get a palindrome (9782772879).

The spelling of 6561161223 in words is "six billion, five hundred sixty-one million, one hundred sixty-one thousand, two hundred twenty-three".