41561816509 has 2 divisors, whose sum is σ = 41561816510. Its totient is φ = 41561816508.

The previous prime is 41561816507. The next prime is 41561816519. The reversal of 41561816509 is 90561816514.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 32461228900 + 9100587609 = 180170^2 + 95397^2 .

It is a cyclic number.

It is not a de Polignac number, because 41561816509 - 2¹ = 41561816507 is a prime.

Together with 41561816507, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (41561816507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20780908254 + 20780908255.

It is an arithmetic number, because the mean of its divisors is an integer number (20780908255).

Almost surely, 2^41561816509 is an apocalyptic number.

It is an amenable number.

41561816509 is a deficient number, since it is larger than the sum of its proper divisors (1).

41561816509 is an equidigital number, since it uses as much as digits as its factorization.

41561816509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 259200, while the sum is 46.

The spelling of 41561816509 in words is "forty-one billion, five hundred sixty-one million, eight hundred sixteen thousand, five hundred nine".