191888161 has 2 divisors, whose sum is σ = 191888162. Its totient is φ = 191888160.

The previous prime is 191888153. The next prime is 191888189. The reversal of 191888161 is 161888191.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 183873600 + 8014561 = 13560^2 + 2831^2 .

It is a cyclic number.

It is not a de Polignac number, because 191888161 - 2³ = 191888153 is a prime.

191888161 is a strobogrammatic number because it is the same when read upside-down.

It is not a weakly prime, because it can be changed into another prime (191888101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95944080 + 95944081.

It is an arithmetic number, because the mean of its divisors is an integer number (95944081).

Almost surely, 2^191888161 is an apocalyptic number.

It is an amenable number.

191888161 is a deficient number, since it is larger than the sum of its proper divisors (1).

191888161 is an equidigital number, since it uses as much as digits as its factorization.

191888161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 27648, while the sum is 43.

The square root of 191888161 is about 13852.3702303974. The cubic root of 191888161 is about 576.7877926517.

The spelling of 191888161 in words is "one hundred ninety-one million, eight hundred eighty-eight thousand, one hundred sixty-one".