125957209 has 4 divisors (see below), whose sum is σ = 143951104. Its totient is φ = 107963316.

The previous prime is 125957197. The next prime is 125957219. The reversal of 125957209 is 902759521.

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: 902759521 = 19 ⋅47513659.

It is a cyclic number.

It is not a de Polignac number, because 125957209 - 2⁹ = 125956697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (125957219) 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, 8996937 + ... + 8996950.

It is an arithmetic number, because the mean of its divisors is an integer number (35987776).

Almost surely, 2^125957209 is an apocalyptic number.

It is an amenable number.

125957209 is a deficient number, since it is larger than the sum of its proper divisors (17993895).

125957209 is an equidigital number, since it uses as much as digits as its factorization.

125957209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17993894.

The product of its (nonzero) digits is 56700, while the sum is 40.

The square root of 125957209 is about 11223.0659358305. The cubic root of 125957209 is about 501.2730346813.

The spelling of 125957209 in words is "one hundred twenty-five million, nine hundred fifty-seven thousand, two hundred nine".