11521540243 has 4 divisors (see below), whose sum is σ = 11521771128. Its totient is φ = 11521309360.

The previous prime is 11521540187. The next prime is 11521540267. The reversal of 11521540243 is 34204512511.

11521540243 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 an emirpimes, since its reverse is a distinct semiprime: 34204512511 = 13 ⋅2631116347.

It is a cyclic number.

It is not a de Polignac number, because 11521540243 - 2¹³ = 11521532051 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11521540643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6013 + ... + 151918.

It is an arithmetic number, because the mean of its divisors is an integer number (2880442782).

Almost surely, 2^11521540243 is an apocalyptic number.

11521540243 is a deficient number, since it is larger than the sum of its proper divisors (230885).

11521540243 is an equidigital number, since it uses as much as digits as its factorization.

11521540243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 230884.

The product of its (nonzero) digits is 4800, while the sum is 28.

The spelling of 11521540243 in words is "eleven billion, five hundred twenty-one million, five hundred forty thousand, two hundred forty-three".