11518381 has 6 divisors (see below), whose sum is σ = 13398990. Its totient is φ = 9872856.

The previous prime is 11518373. The next prime is 11518399. The reversal of 11518381 is 18381511.

It can be written as a sum of positive squares in only one way, i.e., 9357481 + 2160900 = 3059^2 + 1470^2 .

It is not a de Polignac number, because 11518381 - 2³ = 11518373 is a prime.

It is a super-2 number, since 2×11518381² = 265346201722322, 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 (11518301) 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, 117486 + ... + 117583.

It is an arithmetic number, because the mean of its divisors is an integer number (2233165).

Almost surely, 2^11518381 is an apocalyptic number.

It is an amenable number.

11518381 is a deficient number, since it is larger than the sum of its proper divisors (1880609).

11518381 is an equidigital number, since it uses as much as digits as its factorization.

11518381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 235083 (or 235076 counting only the distinct ones).

The product of its digits is 960, while the sum is 28.

The square root of 11518381 is about 3393.8740400905. The cubic root of 11518381 is about 225.8380663154.

Adding to 11518381 its reverse (18381511), we get a palindrome (29899892).

It can be divided in two parts, 115 and 18381, that added together give a square (18496 = 136²).

The spelling of 11518381 in words is "eleven million, five hundred eighteen thousand, three hundred eighty-one".