11111381 has 4 divisors (see below), whose sum is σ = 11143212. Its totient is φ = 11079552.

The previous prime is 11111341. The next prime is 11111393. The reversal of 11111381 is 18311111.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5958481 + 5152900 = 2441^2 + 2270^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11111381 is a prime.

It is a super-2 number, since 2×11111381² = 246925575454322, 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 (11111311) 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 3 ways as a sum of consecutive naturals, for example, 15386 + ... + 16091.

It is an arithmetic number, because the mean of its divisors is an integer number (2785803).

Almost surely, 2^11111381 is an apocalyptic number.

It is an amenable number.

11111381 is a deficient number, since it is larger than the sum of its proper divisors (31831).

11111381 is an equidigital number, since it uses as much as digits as its factorization.

11111381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31830.

The product of its digits is 24, while the sum is 17.

The square root of 11111381 is about 3333.3738164208. The cubic root of 11111381 is about 223.1461234046.

Adding to 11111381 its reverse (18311111), we get a palindrome (29422492).

The spelling of 11111381 in words is "eleven million, one hundred eleven thousand, three hundred eighty-one".