165816541 has 4 divisors (see below), whose sum is σ = 180890784. Its totient is φ = 150742300.

The previous prime is 165816473. The next prime is 165816569. The reversal of 165816541 is 145618561.

165816541 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: 145618561 = 11 ⋅13238051.

It is a cyclic number.

It is not a de Polignac number, because 165816541 - 2²¹ = 163719389 is a prime.

It is an alternating number because its digits alternate between odd and even.

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 165816541.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165814541) 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, 7537105 + ... + 7537126.

It is an arithmetic number, because the mean of its divisors is an integer number (45222696).

Almost surely, 2^165816541 is an apocalyptic number.

165816541 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

165816541 is a deficient number, since it is larger than the sum of its proper divisors (15074243).

165816541 is a wasteful number, since it uses less digits than its factorization.

165816541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15074242.

The product of its digits is 28800, while the sum is 37.

The square root of 165816541 is about 12876.9771685749. The cubic root of 165816541 is about 549.3839283590.

The spelling of 165816541 in words is "one hundred sixty-five million, eight hundred sixteen thousand, five hundred forty-one".