81412729 has 2 divisors, whose sum is σ = 81412730. Its totient is φ = 81412728.

The previous prime is 81412703. The next prime is 81412733. The reversal of 81412729 is 92721418.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 72250000 + 9162729 = 8500^2 + 3027^2 .

It is a cyclic number.

It is not a de Polignac number, because 81412729 - 2⁹ = 81412217 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is equal to p_4747192 and since 81412729 and 4747192 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 81412694 and 81412703.

It is not a weakly prime, because it can be changed into another prime (81412759) 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, 40706364 + 40706365.

It is an arithmetic number, because the mean of its divisors is an integer number (40706365).

Almost surely, 2^81412729 is an apocalyptic number.

It is an amenable number.

81412729 is a deficient number, since it is larger than the sum of its proper divisors (1).

81412729 is an equidigital number, since it uses as much as digits as its factorization.

81412729 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8064, while the sum is 34.

The square root of 81412729 is about 9022.9002543528. The cubic root of 81412729 is about 433.4085131232.

The spelling of 81412729 in words is "eighty-one million, four hundred twelve thousand, seven hundred twenty-nine".