125558509 has 2 divisors, whose sum is σ = 125558510. Its totient is φ = 125558508.

The previous prime is 125558491. The next prime is 125558513. The reversal of 125558509 is 905855521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 85045284 + 40513225 = 9222^2 + 6365^2 .

It is a cyclic number.

It is not a de Polignac number, because 125558509 - 2⁹ = 125557997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (125558569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 62779254 + 62779255.

It is an arithmetic number, because the mean of its divisors is an integer number (62779255).

Almost surely, 2^125558509 is an apocalyptic number.

It is an amenable number.

125558509 is a deficient number, since it is larger than the sum of its proper divisors (1).

125558509 is an equidigital number, since it uses as much as digits as its factorization.

125558509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 90000, while the sum is 40.

The square root of 125558509 is about 11205.2893313827. The cubic root of 125558509 is about 500.7435723189.

The spelling of 125558509 in words is "one hundred twenty-five million, five hundred fifty-eight thousand, five hundred nine".