129765 has 16 divisors (see below), whose sum is σ = 213696. Its totient is φ = 67200.

The previous prime is 129763. The next prime is 129769. The reversal of 129765 is 567921.

129765 = T₂ + T₃ + ... + T₉₁.

129765 = 35² + 36² + ... + 75².

It is not a de Polignac number, because 129765 - 2¹ = 129763 is a prime.

It is an Ulam number.

It is a Curzon number.

It is a congruent number.

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

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 510 + ... + 720.

It is an arithmetic number, because the mean of its divisors is an integer number (13356).

2¹²⁹⁷⁶⁵ is an apocalyptic number.

129765 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

129765 is a deficient number, since it is larger than the sum of its proper divisors (83931).

129765 is a wasteful number, since it uses less digits than its factorization.

129765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 260.

The product of its digits is 3780, while the sum is 30.

The square root of 129765 is about 360.2290937723. The cubic root of 129765 is about 50.6274271051.

Adding to 129765 its sum of digits (30), we get a triangular number (129795 = T₅₀₉).

The spelling of 129765 in words is "one hundred twenty-nine thousand, seven hundred sixty-five".