125909 has 4 divisors (see below), whose sum is σ = 143904. Its totient is φ = 107916.

The previous prime is 125899. The next prime is 125921. The reversal of 125909 is 909521.

It is a happy number.

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.

It is a cyclic number.

It is not a de Polignac number, because 125909 - 2¹⁶ = 60373 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 11.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 125909.

It is not an unprimeable number, because it can be changed into a prime (125929) 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, 8987 + ... + 9000.

It is an arithmetic number, because the mean of its divisors is an integer number (35976).

2¹²⁵⁹⁰⁹ is an apocalyptic number.

It is an amenable number.

125909 is a deficient number, since it is larger than the sum of its proper divisors (17995).

125909 is an equidigital number, since it uses as much as digits as its factorization.

125909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17994.

The product of its (nonzero) digits is 810, while the sum is 26.

The square root of 125909 is about 354.8365821051. The cubic root of 125909 is about 50.1209073924.

The spelling of 125909 in words is "one hundred twenty-five thousand, nine hundred nine".