81412129 has 2 divisors, whose sum is σ = 81412130. Its totient is φ = 81412128.

The previous prime is 81412109. The next prime is 81412147. The reversal of 81412129 is 92121418.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 52896529 + 28515600 = 7273^2 + 5340^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81412129 is a prime.

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

It is equal to p_4747150 and since 81412129 and 4747150 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 = 81412097 and 81412106.

It is not a weakly prime, because it can be changed into another prime (81412109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40706064 + 40706065.

It is an arithmetic number, because the mean of its divisors is an integer number (40706065).

Almost surely, 2^81412129 is an apocalyptic number.

It is an amenable number.

81412129 is a deficient number, since it is larger than the sum of its proper divisors (1).

81412129 is an equidigital number, since it uses as much as digits as its factorization.

81412129 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1152, while the sum is 28.

The square root of 81412129 is about 9022.8670055587. The cubic root of 81412129 is about 433.4074484013.

The spelling of 81412129 in words is "eighty-one million, four hundred twelve thousand, one hundred twenty-nine".