11518990561 has 4 divisors (see below), whose sum is σ = 12405066772. Its totient is φ = 10632914352.

The previous prime is 11518990531. The next prime is 11518990583. The reversal of 11518990561 is 16509981511.

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

It can be written as a sum of positive squares in 2 ways, for example, as 4539390625 + 6979599936 = 67375^2 + 83544^2 .

It is a cyclic number.

It is not a de Polignac number, because 11518990561 - 2⁵ = 11518990529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11518990531) 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, 443038086 + ... + 443038111.

It is an arithmetic number, because the mean of its divisors is an integer number (3101266693).

Almost surely, 2^11518990561 is an apocalyptic number.

It is an amenable number.

11518990561 is a deficient number, since it is larger than the sum of its proper divisors (886076211).

11518990561 is an equidigital number, since it uses as much as digits as its factorization.

11518990561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 886076210.

The product of its (nonzero) digits is 97200, while the sum is 46.

The spelling of 11518990561 in words is "eleven billion, five hundred eighteen million, nine hundred ninety thousand, five hundred sixty-one".