163656191 has 4 divisors (see below), whose sum is σ = 163681800. Its totient is φ = 163630584.

The previous prime is 163656173. The next prime is 163656211. The reversal of 163656191 is 191656361.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 191656361 = 13 ⋅14742797.

It is a cyclic number.

It is not a de Polignac number, because 163656191 - 2²⁶ = 96547327 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (163656121) 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, 5600 + ... + 18938.

It is an arithmetic number, because the mean of its divisors is an integer number (40920450).

Almost surely, 2^163656191 is an apocalyptic number.

163656191 is a deficient number, since it is larger than the sum of its proper divisors (25609).

163656191 is a wasteful number, since it uses less digits than its factorization.

163656191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25608.

The product of its digits is 29160, while the sum is 38.

The square root of 163656191 is about 12792.8179460196. The cubic root of 163656191 is about 546.9875981311.

The spelling of 163656191 in words is "one hundred sixty-three million, six hundred fifty-six thousand, one hundred ninety-one".