165220541 has 4 divisors (see below), whose sum is σ = 165421152. Its totient is φ = 165019932.

The previous prime is 165220537. The next prime is 165220553. The reversal of 165220541 is 145022561.

165220541 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 145022561 = 1009 ⋅143729.

It is a cyclic number.

It is not a de Polignac number, because 165220541 - 2² = 165220537 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 165220541.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165220441) 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, 99065 + ... + 100718.

It is an arithmetic number, because the mean of its divisors is an integer number (41355288).

Almost surely, 2^165220541 is an apocalyptic number.

It is an amenable number.

165220541 is a deficient number, since it is larger than the sum of its proper divisors (200611).

165220541 is an equidigital number, since it uses as much as digits as its factorization.

165220541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 200610.

The product of its (nonzero) digits is 2400, while the sum is 26.

The square root of 165220541 is about 12853.8142588105. The cubic root of 165220541 is about 548.7249150794.

The spelling of 165220541 in words is "one hundred sixty-five million, two hundred twenty thousand, five hundred forty-one".