11616561 has 16 divisors (see below), whose sum is σ = 18774720. Its totient is φ = 7040160.

The previous prime is 11616551. The next prime is 11616589. The reversal of 11616561 is 16561611.

11616561 is a `hidden beast` number, since 1 + 1 + 6 + 1 + 656 + 1 = 666.

11616561 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 11616561 - 2⁵ = 11616529 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (11616511) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19260 + ... + 19853.

It is an arithmetic number, because the mean of its divisors is an integer number (1173420).

Almost surely, 2^11616561 is an apocalyptic number.

11616561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

11616561 is a deficient number, since it is larger than the sum of its proper divisors (7158159).

11616561 is a wasteful number, since it uses less digits than its factorization.

11616561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39133 (or 39127 counting only the distinct ones).

The product of its digits is 1080, while the sum is 27.

The square root of 11616561 is about 3408.3076445650. The cubic root of 11616561 is about 226.4779154819.

The spelling of 11616561 in words is "eleven million, six hundred sixteen thousand, five hundred sixty-one".