166026191 has 2 divisors, whose sum is σ = 166026192. Its totient is φ = 166026190.

The previous prime is 166026109. The next prime is 166026193. The reversal of 166026191 is 191620661.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166026191 is a prime.

Together with 166026193, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166026193) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83013095 + 83013096.

It is an arithmetic number, because the mean of its divisors is an integer number (83013096).

Almost surely, 2^166026191 is an apocalyptic number.

166026191 is a deficient number, since it is larger than the sum of its proper divisors (1).

166026191 is an equidigital number, since it uses as much as digits as its factorization.

166026191 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 166026191 is about 12885.1150945578. The cubic root of 166026191 is about 549.6153685440.

The spelling of 166026191 in words is "one hundred sixty-six million, twenty-six thousand, one hundred ninety-one".