129678805 has 8 divisors (see below), whose sum is σ = 164768472. Its totient is φ = 97640448.

The previous prime is 129678803. The next prime is 129678817. The reversal of 129678805 is 508876921.

It can be written as a sum of positive squares in 4 ways, for example, as 1920996 + 127757809 = 1386^2 + 11303^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 129678805 - 2¹ = 129678803 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129678803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 762732 + ... + 762901.

It is an arithmetic number, because the mean of its divisors is an integer number (20596059).

Almost surely, 2^129678805 is an apocalyptic number.

It is an amenable number.

129678805 is a deficient number, since it is larger than the sum of its proper divisors (35089667).

129678805 is a wasteful number, since it uses less digits than its factorization.

129678805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1525655.

The product of its (nonzero) digits is 241920, while the sum is 46.

The square root of 129678805 is about 11387.6602074351. The cubic root of 129678805 is about 506.1621504831.

The spelling of 129678805 in words is "one hundred twenty-nine million, six hundred seventy-eight thousand, eight hundred five".