125515109 has 2 divisors, whose sum is σ = 125515110. Its totient is φ = 125515108.

The previous prime is 125515081. The next prime is 125515127. The reversal of 125515109 is 901515521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 119290084 + 6225025 = 10922^2 + 2495^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-125515109 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (125515139) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 62757554 + 62757555.

It is an arithmetic number, because the mean of its divisors is an integer number (62757555).

Almost surely, 2^125515109 is an apocalyptic number.

It is an amenable number.

125515109 is a deficient number, since it is larger than the sum of its proper divisors (1).

125515109 is an equidigital number, since it uses as much as digits as its factorization.

125515109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2250, while the sum is 29.

The square root of 125515109 is about 11203.3525785811. The cubic root of 125515109 is about 500.6858707325.

The spelling of 125515109 in words is "one hundred twenty-five million, five hundred fifteen thousand, one hundred nine".