166725191 has 2 divisors, whose sum is σ = 166725192. Its totient is φ = 166725190.

The previous prime is 166725151. The next prime is 166725193. The reversal of 166725191 is 191527661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 166725191 - 2²⁶ = 99616327 is a prime.

Together with 166725193, 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 (166725193) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83362595 + 83362596.

It is an arithmetic number, because the mean of its divisors is an integer number (83362596).

Almost surely, 2^166725191 is an apocalyptic number.

166725191 is a deficient number, since it is larger than the sum of its proper divisors (1).

166725191 is an equidigital number, since it uses as much as digits as its factorization.

166725191 is an evil number, because the sum of its binary digits is even.

The product of its digits is 22680, while the sum is 38.

The square root of 166725191 is about 12912.2109260963. The cubic root of 166725191 is about 550.3856149746.

The spelling of 166725191 in words is "one hundred sixty-six million, seven hundred twenty-five thousand, one hundred ninety-one".