129557 has 4 divisors (see below), whose sum is σ = 137196. Its totient is φ = 121920.

The previous prime is 129553. The next prime is 129581. The reversal of 129557 is 755921.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 755921 = 97 ⋅7793.

It can be written as a sum of positive squares in 2 ways, for example, as 108241 + 21316 = 329^2 + 146^2 .

It is a cyclic number.

It is not a de Polignac number, because 129557 - 2² = 129553 is a prime.

It is a d-powerful number, because it can be written as 1 + 2¹² + 5⁴ + 9⁴ + 5⁴ + 7⁶ .

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129553) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3794 + ... + 3827.

It is an arithmetic number, because the mean of its divisors is an integer number (34299).

2¹²⁹⁵⁵⁷ is an apocalyptic number.

129557 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

129557 is a deficient number, since it is larger than the sum of its proper divisors (7639).

129557 is an equidigital number, since it uses as much as digits as its factorization.

129557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7638.

The product of its digits is 3150, while the sum is 29.

The square root of 129557 is about 359.9402728231. The cubic root of 129557 is about 50.6003624464.

It can be divided in two parts, 129 and 557, that added together give a palindrome (686).

The spelling of 129557 in words is "one hundred twenty-nine thousand, five hundred fifty-seven".