165005543 has 4 divisors (see below), whose sum is σ = 165860688. Its totient is φ = 164150400.

The previous prime is 165005537. The next prime is 165005551. The reversal of 165005543 is 345500561.

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

It is a cyclic number.

It is not a de Polignac number, because 165005543 - 2⁴ = 165005527 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 (165005143) 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, 427283 + ... + 427668.

It is an arithmetic number, because the mean of its divisors is an integer number (41465172).

Almost surely, 2^165005543 is an apocalyptic number.

165005543 is a deficient number, since it is larger than the sum of its proper divisors (855145).

165005543 is an equidigital number, since it uses as much as digits as its factorization.

165005543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 855144.

The product of its (nonzero) digits is 9000, while the sum is 29.

The square root of 165005543 is about 12845.4483378355. The cubic root of 165005543 is about 548.4867970498.

The spelling of 165005543 in words is "one hundred sixty-five million, five thousand, five hundred forty-three".