11535561 has 8 divisors (see below), whose sum is σ = 17089760. Its totient is φ = 7690356.

The previous prime is 11535551. The next prime is 11535593. The reversal of 11535561 is 16553511.

It is not a de Polignac number, because 11535561 - 2⁵ = 11535529 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 427243 = 11535561 / (1 + 1 + 5 + 3 + 5 + 5 + 6 + 1).

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (11535541) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 213595 + ... + 213648.

It is an arithmetic number, because the mean of its divisors is an integer number (2136220).

Almost surely, 2^11535561 is an apocalyptic number.

It is an amenable number.

11535561 is a deficient number, since it is larger than the sum of its proper divisors (5554199).

11535561 is an equidigital number, since it uses as much as digits as its factorization.

11535561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 427252 (or 427246 counting only the distinct ones).

The product of its digits is 2250, while the sum is 27.

The square root of 11535561 is about 3396.4041278976. The cubic root of 11535561 is about 225.9502918843.

The spelling of 11535561 in words is "eleven million, five hundred thirty-five thousand, five hundred sixty-one".