129807761 has 2 divisors, whose sum is σ = 129807762. Its totient is φ = 129807760.

The previous prime is 129807751. The next prime is 129807781. The reversal of 129807761 is 167708921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 69822736 + 59985025 = 8356^2 + 7745^2 .

It is a cyclic number.

It is not a de Polignac number, because 129807761 - 2¹⁴ = 129791377 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (129807721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64903880 + 64903881.

It is an arithmetic number, because the mean of its divisors is an integer number (64903881).

Almost surely, 2^129807761 is an apocalyptic number.

It is an amenable number.

129807761 is a deficient number, since it is larger than the sum of its proper divisors (1).

129807761 is an equidigital number, since it uses as much as digits as its factorization.

129807761 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 42336, while the sum is 41.

The square root of 129807761 is about 11393.3208942784. The cubic root of 129807761 is about 506.3298751984.

The spelling of 129807761 in words is "one hundred twenty-nine million, eight hundred seven thousand, seven hundred sixty-one".