81000481 has 2 divisors, whose sum is σ = 81000482. Its totient is φ = 81000480.

The previous prime is 81000467. The next prime is 81000487. The reversal of 81000481 is 18400018.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 60606225 + 20394256 = 7785^2 + 4516^2 .

It is a cyclic number.

It is not a de Polignac number, because 81000481 - 2⁵ = 81000449 is a prime.

It is a super-2 number, since 2×81000481² = 13122155844462722, which contains 22 as substring.

81000481 is a modest number, since divided by 481 gives 81 as remainder.

It is not a weakly prime, because it can be changed into another prime (81000487) 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, 40500240 + 40500241.

It is an arithmetic number, because the mean of its divisors is an integer number (40500241).

Almost surely, 2^81000481 is an apocalyptic number.

It is an amenable number.

81000481 is a deficient number, since it is larger than the sum of its proper divisors (1).

81000481 is an equidigital number, since it uses as much as digits as its factorization.

81000481 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 256, while the sum is 22.

The square root of 81000481 is about 9000.0267221826. The cubic root of 81000481 is about 432.6757275375.

Adding to 81000481 its reverse (18400018), we get a palindrome (99400499).

The spelling of 81000481 in words is "eighty-one million, four hundred eighty-one", and thus it is an aban number.