125306509133521 has 9 divisors (see below), whose sum is σ = 127047379249179. Its totient is φ = 123589175640336.

The previous prime is 125306509133401. The next prime is 125306509133527. The reversal of 125306509133521 is 125331905603521.

It is a happy number.

The square root of 125306509133521 is 11194039.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 71130078838225 + 54176430295296 = 8433865^2 + 7360464^2 .

It is not a de Polignac number, because 125306509133521 - 2⁹ = 125306509133009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (125306509133527) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 817088176 + ... + 817241518.

It is an arithmetic number, because the mean of its divisors is an integer number (14116375472131).

Almost surely, 2^{125306509133521} is an apocalyptic number.

125306509133521 is the 11194039-th square number.

125306509133521 is the 5597020-th centered octagonal number.

It is an amenable number.

125306509133521 is a deficient number, since it is larger than the sum of its proper divisors (1740870115658).

125306509133521 is an frugal number, since it uses more digits than its factorization.

125306509133521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 306832 (or 153416 counting only the distinct ones).

The product of its (nonzero) digits is 729000, while the sum is 46.

The spelling of 125306509133521 in words is "one hundred twenty-five trillion, three hundred six billion, five hundred nine million, one hundred thirty-three thousand, five hundred twenty-one".