129378717185 has 4 divisors (see below), whose sum is σ = 155254460628. Its totient is φ = 103502973744.

The previous prime is 129378717109. The next prime is 129378717187. The reversal of 129378717185 is 581717873921.

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 82075947121 + 47302770064 = 286489^2 + 217492^2 .

It is a cyclic number.

It is not a de Polignac number, because 129378717185 - 2¹⁰ = 129378716161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129378717187) 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, 12937871714 + ... + 12937871723.

It is an arithmetic number, because the mean of its divisors is an integer number (38813615157).

Almost surely, 2^129378717185 is an apocalyptic number.

It is an amenable number.

129378717185 is a deficient number, since it is larger than the sum of its proper divisors (25875743443).

129378717185 is an equidigital number, since it uses as much as digits as its factorization.

129378717185 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25875743442.

The product of its digits is 5927040, while the sum is 59.

The spelling of 129378717185 in words is "one hundred twenty-nine billion, three hundred seventy-eight million, seven hundred seventeen thousand, one hundred eighty-five".