111111381 has 6 divisors (see below), whose sum is σ = 160494230. Its totient is φ = 74074248.

The previous prime is 111111361. The next prime is 111111391. The reversal of 111111381 is 183111111.

It can be written as a sum of positive squares in only one way, i.e., 107308881 + 3802500 = 10359^2 + 1950^2 .

It is not a de Polignac number, because 111111381 - 2⁹ = 111110869 is a prime.

It is a super-2 number, since 2×111111381² = 24691477975454322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111111331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6172846 + ... + 6172863.

Almost surely, 2^111111381 is an apocalyptic number.

It is an amenable number.

111111381 is a deficient number, since it is larger than the sum of its proper divisors (49382849).

111111381 is a wasteful number, since it uses less digits than its factorization.

111111381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12345715 (or 12345712 counting only the distinct ones).

The product of its digits is 24, while the sum is 18.

The square root of 111111381 is about 10540.9383358409. The cubic root of 111111381 is about 480.7502460160.

Adding to 111111381 its reverse (183111111), we get a palindrome (294222492).

The spelling of 111111381 in words is "one hundred eleven million, one hundred eleven thousand, three hundred eighty-one".