11111681 has 6 divisors (see below), whose sum is σ = 12925890. Its totient is φ = 9524256.

The previous prime is 11111677. The next prime is 11111687. The reversal of 11111681 is 18611111.

It can be written as a sum of positive squares in only one way, i.e., 7075600 + 4036081 = 2660^2 + 2009^2 .

It is not a de Polignac number, because 11111681 - 2² = 11111677 is a prime.

It is a super-2 number, since 2×11111681² = 246938909291522, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (11111687) 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, 113336 + ... + 113433.

It is an arithmetic number, because the mean of its divisors is an integer number (2154315).

Almost surely, 2^11111681 is an apocalyptic number.

It is an amenable number.

11111681 is a deficient number, since it is larger than the sum of its proper divisors (1814209).

11111681 is an equidigital number, since it uses as much as digits as its factorization.

11111681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 226783 (or 226776 counting only the distinct ones).

The product of its digits is 48, while the sum is 20.

The square root of 11111681 is about 3333.4188155706. The cubic root of 11111681 is about 223.1481316528.

Adding to 11111681 its reverse (18611111), we get a palindrome (29722792).

The spelling of 11111681 in words is "eleven million, one hundred eleven thousand, six hundred eighty-one".