11565541 has 4 divisors (see below), whose sum is σ = 12455212. Its totient is φ = 10675872.

The previous prime is 11565487. The next prime is 11565551. The reversal of 11565541 is 14556511.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 14556511 = 47 ⋅309713.

It can be written as a sum of positive squares in 2 ways, for example, as 2414916 + 9150625 = 1554^2 + 3025^2 .

It is a cyclic number.

It is not a de Polignac number, because 11565541 - 2⁷ = 11565413 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 (11565551) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 444816 + ... + 444841.

It is an arithmetic number, because the mean of its divisors is an integer number (3113803).

Almost surely, 2^11565541 is an apocalyptic number.

It is an amenable number.

11565541 is a deficient number, since it is larger than the sum of its proper divisors (889671).

11565541 is an equidigital number, since it uses as much as digits as its factorization.

11565541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 889670.

The product of its digits is 3000, while the sum is 28.

The square root of 11565541 is about 3400.8147553197. The cubic root of 11565541 is about 226.1458647989.

It can be divided in two parts, 115 and 65541, that added together give a palindrome (65656).

The spelling of 11565541 in words is "eleven million, five hundred sixty-five thousand, five hundred forty-one".