129761 has 6 divisors (see below), whose sum is σ = 138150. Its totient is φ = 121856.

The previous prime is 129757. The next prime is 129763. The reversal of 129761 is 167921.

It can be written as a sum of positive squares in 3 ways, for example, as 59536 + 70225 = 244^2 + 265^2 .

It is not a de Polignac number, because 129761 - 2² = 129757 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 129761.

It is not an unprimeable number, because it can be changed into a prime (129763) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 65 + ... + 513.

It is an arithmetic number, because the mean of its divisors is an integer number (23025).

2¹²⁹⁷⁶¹ is an apocalyptic number.

It is an amenable number.

129761 is a deficient number, since it is larger than the sum of its proper divisors (8389).

129761 is an equidigital number, since it uses as much as digits as its factorization.

129761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 483 (or 466 counting only the distinct ones).

The product of its digits is 756, while the sum is 26.

The square root of 129761 is about 360.2235417071. The cubic root of 129761 is about 50.6269069037.

The spelling of 129761 in words is "one hundred twenty-nine thousand, seven hundred sixty-one".