6561011 has 2 divisors, whose sum is σ = 6561012. Its totient is φ = 6561010.

The previous prime is 6561007. The next prime is 6561013. The reversal of 6561011 is 1101656.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6561011 - 2² = 6561007 is a prime.

Together with 6561013, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (6561013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3280505 + 3280506.

It is an arithmetic number, because the mean of its divisors is an integer number (3280506).

Almost surely, 2^6561011 is an apocalyptic number.

6561011 is a deficient number, since it is larger than the sum of its proper divisors (1).

6561011 is an equidigital number, since it uses as much as digits as its factorization.

6561011 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 180, while the sum is 20.

The square root of 6561011 is about 2561.4470519611. The cubic root of 6561011 is about 187.2076486970.

Adding to 6561011 its reverse (1101656), we get a palindrome (7662667).

The spelling of 6561011 in words is "six million, five hundred sixty-one thousand, eleven".