129081512785 has 4 divisors (see below), whose sum is σ = 154897815348. Its totient is φ = 103265210224.

The previous prime is 129081512783. The next prime is 129081512887. The reversal of 129081512785 is 587215180921.

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 13683384576 + 115398128209 = 116976^2 + 339703^2 .

It is a cyclic number.

It is not a de Polignac number, because 129081512785 - 2¹ = 129081512783 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129081512783) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12908151274 + ... + 12908151283.

It is an arithmetic number, because the mean of its divisors is an integer number (38724453837).

Almost surely, 2^129081512785 is an apocalyptic number.

It is an amenable number.

129081512785 is a deficient number, since it is larger than the sum of its proper divisors (25816302563).

129081512785 is an equidigital number, since it uses as much as digits as its factorization.

129081512785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25816302562.

The product of its (nonzero) digits is 403200, while the sum is 49.

The spelling of 129081512785 in words is "one hundred twenty-nine billion, eighty-one million, five hundred twelve thousand, seven hundred eighty-five".