125661661 has 2 divisors, whose sum is σ = 125661662. Its totient is φ = 125661660.

The previous prime is 125661629. The next prime is 125661667. The reversal of 125661661 is 166166521.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 114811225 + 10850436 = 10715^2 + 3294^2 .

It is a cyclic number.

It is not a de Polignac number, because 125661661 - 2⁵ = 125661629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (125661667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 62830830 + 62830831.

It is an arithmetic number, because the mean of its divisors is an integer number (62830831).

Almost surely, 2^125661661 is an apocalyptic number.

It is an amenable number.

125661661 is a deficient number, since it is larger than the sum of its proper divisors (1).

125661661 is an equidigital number, since it uses as much as digits as its factorization.

125661661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12960, while the sum is 34.

The square root of 125661661 is about 11209.8912126746. The cubic root of 125661661 is about 500.8806626227.

The spelling of 125661661 in words is "one hundred twenty-five million, six hundred sixty-one thousand, six hundred sixty-one".