125399861 has 2 divisors, whose sum is σ = 125399862. Its totient is φ = 125399860.

The previous prime is 125399849. The next prime is 125399873. The reversal of 125399861 is 168993521.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (125399849) and next prime (125399873).

It can be written as a sum of positive squares in only one way, i.e., 105987025 + 19412836 = 10295^2 + 4406^2 .

It is a cyclic number.

It is not a de Polignac number, because 125399861 - 2⁶ = 125399797 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (125399801) 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, 62699930 + 62699931.

It is an arithmetic number, because the mean of its divisors is an integer number (62699931).

Almost surely, 2^125399861 is an apocalyptic number.

It is an amenable number.

125399861 is a deficient number, since it is larger than the sum of its proper divisors (1).

125399861 is an equidigital number, since it uses as much as digits as its factorization.

125399861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 116640, while the sum is 44.

The square root of 125399861 is about 11198.2079369871. The cubic root of 125399861 is about 500.5325805146.

The spelling of 125399861 in words is "one hundred twenty-five million, three hundred ninety-nine thousand, eight hundred sixty-one".