11563681 has 8 divisors (see below), whose sum is σ = 11982600. Its totient is φ = 11151360.

The previous prime is 11563667. The next prime is 11563693. The reversal of 11563681 is 18636511.

It can be written as a sum of positive squares in 4 ways, for example, as 173056 + 11390625 = 416^2 + 3375^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 11563681 - 2⁵ = 11563649 is a prime.

It is a super-2 number, since 2×11563681² = 267437436539522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11563631) 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, 2065 + ... + 5233.

It is an arithmetic number, because the mean of its divisors is an integer number (1497825).

Almost surely, 2^11563681 is an apocalyptic number.

It is an amenable number.

11563681 is a deficient number, since it is larger than the sum of its proper divisors (418919).

11563681 is an equidigital number, since it uses as much as digits as its factorization.

11563681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3299.

The product of its digits is 4320, while the sum is 31.

The square root of 11563681 is about 3400.5412804435. The cubic root of 11563681 is about 226.1337410294.

The spelling of 11563681 in words is "eleven million, five hundred sixty-three thousand, six hundred eighty-one".