166126391 has 2 divisors, whose sum is σ = 166126392. Its totient is φ = 166126390.

The previous prime is 166126379. The next prime is 166126403. The reversal of 166126391 is 193621661.

It is a balanced prime because it is at equal distance from previous prime (166126379) and next prime (166126403).

It is a cyclic number.

It is not a de Polignac number, because 166126391 - 2¹⁰ = 166125367 is a prime.

It is a Sophie Germain 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 (166126351) 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, 83063195 + 83063196.

It is an arithmetic number, because the mean of its divisors is an integer number (83063196).

Almost surely, 2^166126391 is an apocalyptic number.

166126391 is a deficient number, since it is larger than the sum of its proper divisors (1).

166126391 is an equidigital number, since it uses as much as digits as its factorization.

166126391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11664, while the sum is 35.

The square root of 166126391 is about 12889.0027154935. The cubic root of 166126391 is about 549.7259141240.

The spelling of 166126391 in words is "one hundred sixty-six million, one hundred twenty-six thousand, three hundred ninety-one".