129500065 has 4 divisors (see below), whose sum is σ = 155400084. Its totient is φ = 103600048.

The previous prime is 129500027. The next prime is 129500081. The reversal of 129500065 is 560005921.

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 28376929 + 101123136 = 5327^2 + 10056^2 .

It is a cyclic number.

It is not a de Polignac number, because 129500065 - 2¹⁵ = 129467297 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12950002 + ... + 12950011.

It is an arithmetic number, because the mean of its divisors is an integer number (38850021).

Almost surely, 2^129500065 is an apocalyptic number.

It is an amenable number.

129500065 is a deficient number, since it is larger than the sum of its proper divisors (25900019).

129500065 is an equidigital number, since it uses as much as digits as its factorization.

129500065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25900018.

The product of its (nonzero) digits is 2700, while the sum is 28.

The square root of 129500065 is about 11379.8095326767. The cubic root of 129500065 is about 505.9294909747.

Adding to 129500065 its reverse (560005921), we get a palindrome (689505986).

The spelling of 129500065 in words is "one hundred twenty-nine million, five hundred thousand, sixty-five".