11315561 has 6 divisors (see below), whose sum is σ = 11507886. Its totient is φ = 11126400.

The previous prime is 11315543. The next prime is 11315567. The reversal of 11315561 is 16551311.

11315561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 133225 + 11182336 = 365^2 + 3344^2 .

It is a de Polignac number, because none of the positive numbers 2^k-11315561 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (11315567) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2201 + ... + 5241.

It is an arithmetic number, because the mean of its divisors is an integer number (1917981).

Almost surely, 2^11315561 is an apocalyptic number.

It is an amenable number.

11315561 is a deficient number, since it is larger than the sum of its proper divisors (192325).

11315561 is an frugal number, since it uses more digits than its factorization.

11315561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3163 (or 3102 counting only the distinct ones).

The product of its digits is 450, while the sum is 23.

The square root of 11315561 is about 3363.8610256668. The cubic root of 11315561 is about 224.5046617518.

Adding to 11315561 its reverse (16551311), we get a palindrome (27866872).

The spelling of 11315561 in words is "eleven million, three hundred fifteen thousand, five hundred sixty-one".