1138111381 has 16 divisors (see below), whose sum is σ = 1309248000. Its totient is φ = 978447600.

The previous prime is 1138111349. The next prime is 1138111399. The reversal of 1138111381 is 1831118311.

It is a cyclic number.

It is not a de Polignac number, because 1138111381 - 2⁵ = 1138111349 is a prime.

It is a super-2 number, since 2×1138111381² = 2590595031123454322, 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 (1138111301) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 120646 + ... + 129736.

It is an arithmetic number, because the mean of its divisors is an integer number (81828000).

Almost surely, 2^1138111381 is an apocalyptic number.

1138111381 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1138111381 is a deficient number, since it is larger than the sum of its proper divisors (171136619).

1138111381 is a wasteful number, since it uses less digits than its factorization.

1138111381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9720.

The product of its digits is 576, while the sum is 28.

The square root of 1138111381 is about 33735.9064054903. The cubic root of 1138111381 is about 1044.0667265646.

Adding to 1138111381 its reverse (1831118311), we get a palindrome (2969229692).

The spelling of 1138111381 in words is "one billion, one hundred thirty-eight million, one hundred eleven thousand, three hundred eighty-one".