81804241 has 2 divisors, whose sum is σ = 81804242. Its totient is φ = 81804240.

The previous prime is 81804223. The next prime is 81804251. The reversal of 81804241 is 14240818.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 53714241 + 28090000 = 7329^2 + 5300^2 .

It is a cyclic number.

It is not a de Polignac number, because 81804241 - 2⁷ = 81804113 is a prime.

It is not a weakly prime, because it can be changed into another prime (81804211) 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 as a sum of consecutive naturals, namely, 40902120 + 40902121.

It is an arithmetic number, because the mean of its divisors is an integer number (40902121).

Almost surely, 2^81804241 is an apocalyptic number.

It is an amenable number.

81804241 is a deficient number, since it is larger than the sum of its proper divisors (1).

81804241 is an equidigital number, since it uses as much as digits as its factorization.

81804241 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2048, while the sum is 28.

The square root of 81804241 is about 9044.5696967849. The cubic root of 81804241 is about 434.1021530369.

It can be divided in two parts, 8180 and 4241, that added together give a palindrome (12421).

The spelling of 81804241 in words is "eighty-one million, eight hundred four thousand, two hundred forty-one".