41981809 has 2 divisors, whose sum is σ = 41981810. Its totient is φ = 41981808.

The previous prime is 41981801. The next prime is 41981813. The reversal of 41981809 is 90818914.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25603600 + 16378209 = 5060^2 + 4047^2 .

It is a cyclic number.

It is not a de Polignac number, because 41981809 - 2³ = 41981801 is a prime.

It is not a weakly prime, because it can be changed into another prime (41981801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20990904 + 20990905.

It is an arithmetic number, because the mean of its divisors is an integer number (20990905).

Almost surely, 2^41981809 is an apocalyptic number.

It is an amenable number.

41981809 is a deficient number, since it is larger than the sum of its proper divisors (1).

41981809 is an equidigital number, since it uses as much as digits as its factorization.

41981809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20736, while the sum is 40.

The square root of 41981809 is about 6479.3370802884. The cubic root of 41981809 is about 347.5524727966.

It can be divided in two parts, 419 and 81809, that added together give a palindrome (82228).

The spelling of 41981809 in words is "forty-one million, nine hundred eighty-one thousand, eight hundred nine".