163791565 has 24 divisors (see below), whose sum is σ = 236534040. Its totient is φ = 108436608.

The previous prime is 163791559. The next prime is 163791577. The reversal of 163791565 is 565197361.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 34082244 + 129709321 = 5838^2 + 11389^2 .

It is not a de Polignac number, because 163791565 - 2³ = 163791557 is a prime.

It is a Smith number, since the sum of its digits (43) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4422 + ... + 18631.

It is an arithmetic number, because the mean of its divisors is an integer number (9855585).

Almost surely, 2^163791565 is an apocalyptic number.

It is an amenable number.

163791565 is a deficient number, since it is larger than the sum of its proper divisors (72742475).

163791565 is a wasteful number, since it uses less digits than its factorization.

163791565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23101 (or 23094 counting only the distinct ones).

The product of its digits is 170100, while the sum is 43.

The square root of 163791565 is about 12798.1078679624. The cubic root of 163791565 is about 547.1383766034.

The spelling of 163791565 in words is "one hundred sixty-three million, seven hundred ninety-one thousand, five hundred sixty-five".