111311681 has 6 divisors (see below), whose sum is σ = 120532950. Its totient is φ = 102749088.

The previous prime is 111311647. The next prime is 111311689. The reversal of 111311681 is 186113111.

It can be written as a sum of positive squares in 3 ways, for example, as 3671056 + 107640625 = 1916^2 + 10375^2 .

It is not a de Polignac number, because 111311681 - 2¹⁸ = 111049537 is a prime.

It is a super-2 number, since 2×111311681² = 24780580654091522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (111311689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 329156 + ... + 329493.

It is an arithmetic number, because the mean of its divisors is an integer number (20088825).

Almost surely, 2^111311681 is an apocalyptic number.

It is an amenable number.

111311681 is a deficient number, since it is larger than the sum of its proper divisors (9221269).

111311681 is an equidigital number, since it uses as much as digits as its factorization.

111311681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 658675 (or 658662 counting only the distinct ones).

The product of its digits is 144, while the sum is 23.

The square root of 111311681 is about 10550.4351095109. The cubic root of 111311681 is about 481.0389547219.

Adding to 111311681 its reverse (186113111), we get a palindrome (297424792).

The spelling of 111311681 in words is "one hundred eleven million, three hundred eleven thousand, six hundred eighty-one".