125355809 has 2 divisors, whose sum is σ = 125355810. Its totient is φ = 125355808.

The previous prime is 125355803. The next prime is 125355827. The reversal of 125355809 is 908553521.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71656225 + 53699584 = 8465^2 + 7328^2 .

It is a cyclic number.

It is not a de Polignac number, because 125355809 - 2⁸ = 125355553 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (125355803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 62677904 + 62677905.

It is an arithmetic number, because the mean of its divisors is an integer number (62677905).

Almost surely, 2^125355809 is an apocalyptic number.

It is an amenable number.

125355809 is a deficient number, since it is larger than the sum of its proper divisors (1).

125355809 is an equidigital number, since it uses as much as digits as its factorization.

125355809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 54000, while the sum is 38.

The square root of 125355809 is about 11196.2408423542. The cubic root of 125355809 is about 500.4739625770.

The spelling of 125355809 in words is "one hundred twenty-five million, three hundred fifty-five thousand, eight hundred nine".