129257 has 4 divisors (see below), whose sum is σ = 136080. Its totient is φ = 122436.

The previous prime is 129229. The next prime is 129263. The reversal of 129257 is 752921.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 752921 = 13 ⋅57917.

It is not a de Polignac number, because 129257 - 2⁶ = 129193 is a prime.

It is a Duffinian number.

It is a plaindrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (129277) 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 3 ways as a sum of consecutive naturals, for example, 3383 + ... + 3420.

It is an arithmetic number, because the mean of its divisors is an integer number (34020).

2¹²⁹²⁵⁷ is an apocalyptic number.

It is an amenable number.

129257 is a deficient number, since it is larger than the sum of its proper divisors (6823).

129257 is an equidigital number, since it uses as much as digits as its factorization.

129257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6822.

The product of its digits is 1260, while the sum is 26.

The square root of 129257 is about 359.5232954900. The cubic root of 129257 is about 50.5612758134.

It can be divided in two parts, 129 and 257, that multiplied together give a triangular number (33153 = T₂₅₇).

The spelling of 129257 in words is "one hundred twenty-nine thousand, two hundred fifty-seven".