165656191 has 2 divisors, whose sum is σ = 165656192. Its totient is φ = 165656190.

The previous prime is 165656159. The next prime is 165656203. The reversal of 165656191 is 191656561.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 165656191 - 2⁵ = 165656159 is a prime.

It is equal to p_9273478 and since 165656191 and 9273478 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165656291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82828095 + 82828096.

It is an arithmetic number, because the mean of its divisors is an integer number (82828096).

Almost surely, 2^165656191 is an apocalyptic number.

165656191 is a deficient number, since it is larger than the sum of its proper divisors (1).

165656191 is an equidigital number, since it uses as much as digits as its factorization.

165656191 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 48600, while the sum is 40.

The square root of 165656191 is about 12870.7494342793. The cubic root of 165656191 is about 549.2067805221.

It can be divided in two parts, 1656561 and 91, that multiplied together give a palindrome (150747051).

The spelling of 165656191 in words is "one hundred sixty-five million, six hundred fifty-six thousand, one hundred ninety-one".