6561895369 has 2 divisors, whose sum is σ = 6561895370. Its totient is φ = 6561895368.

The previous prime is 6561895367. The next prime is 6561895387. The reversal of 6561895369 is 9635981656.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6559056144 + 2839225 = 80988^2 + 1685^2 .

It is a cyclic number.

It is not a de Polignac number, because 6561895369 - 2¹ = 6561895367 is a prime.

It is a super-2 number, since 2×6561895369² = 86116941667407292322, which contains 22 as substring.

Together with 6561895367, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (6561895367) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3280947684 + 3280947685.

It is an arithmetic number, because the mean of its divisors is an integer number (3280947685).

Almost surely, 2^6561895369 is an apocalyptic number.

It is an amenable number.

6561895369 is a deficient number, since it is larger than the sum of its proper divisors (1).

6561895369 is an equidigital number, since it uses as much as digits as its factorization.

6561895369 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10497600, while the sum is 58.

The square root of 6561895369 is about 81005.5267805845. The cubic root of 6561895369 is about 1872.1605965701.

The spelling of 6561895369 in words is "six billion, five hundred sixty-one million, eight hundred ninety-five thousand, three hundred sixty-nine".