125666491 has 2 divisors, whose sum is σ = 125666492. Its totient is φ = 125666490.

The previous prime is 125666461. The next prime is 125666531. The reversal of 125666491 is 194666521.

It is a happy number.

It is an a-pointer prime, because the next prime (125666531) can be obtained adding 125666491 to its sum of digits (40).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 125666491 - 2⁹ = 125665979 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (125666461) 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, 62833245 + 62833246.

It is an arithmetic number, because the mean of its divisors is an integer number (62833246).

Almost surely, 2^125666491 is an apocalyptic number.

125666491 is a deficient number, since it is larger than the sum of its proper divisors (1).

125666491 is an equidigital number, since it uses as much as digits as its factorization.

125666491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 77760, while the sum is 40.

The square root of 125666491 is about 11210.1066453446. The cubic root of 125666491 is about 500.8870799144.

The spelling of 125666491 in words is "one hundred twenty-five million, six hundred sixty-six thousand, four hundred ninety-one".