81081029 has 2 divisors, whose sum is σ = 81081030. Its totient is φ = 81081028.

The previous prime is 81081019. The next prime is 81081031. The reversal of 81081029 is 92018018.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61984129 + 19096900 = 7873^2 + 4370^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81081029 is a prime.

It is a Sophie Germain prime.

Together with 81081031, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 81080992 and 81081010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81081019) 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, 40540514 + 40540515.

It is an arithmetic number, because the mean of its divisors is an integer number (40540515).

Almost surely, 2^81081029 is an apocalyptic number.

It is an amenable number.

81081029 is a deficient number, since it is larger than the sum of its proper divisors (1).

81081029 is an equidigital number, since it uses as much as digits as its factorization.

81081029 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1152, while the sum is 29.

The square root of 81081029 is about 9004.5004858682. The cubic root of 81081029 is about 432.8190996027.

The spelling of 81081029 in words is "eighty-one million, eighty-one thousand, twenty-nine".