163565643 has 4 divisors (see below), whose sum is σ = 218087528. Its totient is φ = 109043760.

The previous prime is 163565617. The next prime is 163565681. The reversal of 163565643 is 346565361.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 346565361 = 3 ⋅115521787.

It is not a de Polignac number, because 163565643 - 2⁸ = 163565387 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (163565543) 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, 27260938 + ... + 27260943.

It is an arithmetic number, because the mean of its divisors is an integer number (54521882).

Almost surely, 2^163565643 is an apocalyptic number.

163565643 is a deficient number, since it is larger than the sum of its proper divisors (54521885).

163565643 is an equidigital number, since it uses as much as digits as its factorization.

163565643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54521884.

The product of its digits is 194400, while the sum is 39.

The square root of 163565643 is about 12789.2784393804. The cubic root of 163565643 is about 546.8867000838.

The spelling of 163565643 in words is "one hundred sixty-three million, five hundred sixty-five thousand, six hundred forty-three".