11115681 has 4 divisors (see below), whose sum is σ = 14820912. Its totient is φ = 7410452.

The previous prime is 11115679. The next prime is 11115683. The reversal of 11115681 is 18651111.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18651111 = 3 ⋅6217037.

It is an interprime number because it is at equal distance from previous prime (11115679) and next prime (11115683).

It is a cyclic number.

It is not a de Polignac number, because 11115681 - 2¹ = 11115679 is a prime.

It is a super-2 number, since 2×11115681² = 247116728187522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (11115683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1852611 + ... + 1852616.

It is an arithmetic number, because the mean of its divisors is an integer number (3705228).

Almost surely, 2^11115681 is an apocalyptic number.

It is an amenable number.

11115681 is a deficient number, since it is larger than the sum of its proper divisors (3705231).

11115681 is an equidigital number, since it uses as much as digits as its factorization.

11115681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3705230.

The product of its digits is 240, while the sum is 24.

The square root of 11115681 is about 3334.0187461980. The cubic root of 11115681 is about 223.1749048429.

Adding to 11115681 its reverse (18651111), we get a palindrome (29766792).

The spelling of 11115681 in words is "eleven million, one hundred fifteen thousand, six hundred eighty-one".