165804563 has 4 divisors (see below), whose sum is σ = 166663848. Its totient is φ = 164945280.

The previous prime is 165804521. The next prime is 165804601. The reversal of 165804563 is 365408561.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165804563 is a prime.

It is a super-2 number, since 2×165804563² = 54982306223241938, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165804503) 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, 429353 + ... + 429738.

It is an arithmetic number, because the mean of its divisors is an integer number (41665962).

Almost surely, 2^165804563 is an apocalyptic number.

165804563 is a deficient number, since it is larger than the sum of its proper divisors (859285).

165804563 is an equidigital number, since it uses as much as digits as its factorization.

165804563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 859284.

The product of its (nonzero) digits is 86400, while the sum is 38.

The square root of 165804563 is about 12876.5120665497. The cubic root of 165804563 is about 549.3706995237.

The spelling of 165804563 in words is "one hundred sixty-five million, eight hundred four thousand, five hundred sixty-three".