129040081 has 4 divisors (see below), whose sum is σ = 136630692. Its totient is φ = 121449472.

The previous prime is 129040069. The next prime is 129040103. The reversal of 129040081 is 180040921.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 44675856 + 84364225 = 6684^2 + 9185^2 .

It is a cyclic number.

It is not a de Polignac number, because 129040081 - 2⁵ = 129040049 is a prime.

It is a super-2 number, since 2×129040081² = 33302685008973122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129040031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3795280 + ... + 3795313.

It is an arithmetic number, because the mean of its divisors is an integer number (34157673).

Almost surely, 2^129040081 is an apocalyptic number.

It is an amenable number.

129040081 is a deficient number, since it is larger than the sum of its proper divisors (7590611).

129040081 is an equidigital number, since it uses as much as digits as its factorization.

129040081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7590610.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 129040081 is about 11359.5810222032. The cubic root of 129040081 is about 505.3297601156.

The spelling of 129040081 in words is "one hundred twenty-nine million, forty thousand, eighty-one".