191208161 has 4 divisors (see below), whose sum is σ = 191362500. Its totient is φ = 191053824.

The previous prime is 191208139. The next prime is 191208167. The reversal of 191208161 is 161802191.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 122235136 + 68973025 = 11056^2 + 8305^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-191208161 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (191208167) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 75296 + ... + 77793.

It is an arithmetic number, because the mean of its divisors is an integer number (47840625).

Almost surely, 2^191208161 is an apocalyptic number.

It is an amenable number.

191208161 is a deficient number, since it is larger than the sum of its proper divisors (154339).

191208161 is a wasteful number, since it uses less digits than its factorization.

191208161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154338.

The product of its (nonzero) digits is 864, while the sum is 29.

The square root of 191208161 is about 13827.8039109614. The cubic root of 191208161 is about 576.1056593481.

The spelling of 191208161 in words is "one hundred ninety-one million, two hundred eight thousand, one hundred sixty-one".