129999731564509 has 2 divisors, whose sum is σ = 129999731564510. Its totient is φ = 129999731564508.

The previous prime is 129999731564491. The next prime is 129999731564543. The reversal of 129999731564509 is 905465137999921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 95621995822500 + 34377735742009 = 9778650^2 + 5863253^2 .

It is a cyclic number.

It is not a de Polignac number, because 129999731564509 - 2⁵ = 129999731564477 is a prime.

It is a super-2 number, since 2×129999731564509² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129999731561509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64999865782254 + 64999865782255.

It is an arithmetic number, because the mean of its divisors is an integer number (64999865782255).

Almost surely, 2^{129999731564509} is an apocalyptic number.

It is an amenable number.

129999731564509 is a deficient number, since it is larger than the sum of its proper divisors (1).

129999731564509 is an equidigital number, since it uses as much as digits as its factorization.

129999731564509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1488034800, while the sum is 79.

The spelling of 129999731564509 in words is "one hundred twenty-nine trillion, nine hundred ninety-nine billion, seven hundred thirty-one million, five hundred sixty-four thousand, five hundred nine".