18181131 has 8 divisors (see below), whose sum is σ = 24805440. Its totient is φ = 11838792.

The previous prime is 18181117. The next prime is 18181147. The reversal of 18181131 is 13118181.

18181131 = T₈₉₈ + T₈₉₉ + ... + T₉₄₀.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18181131 - 2⁹ = 18180619 is a prime.

It is a super-2 number, since 2×18181131² = 661107048878322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18181181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 70341 + ... + 70598.

It is an arithmetic number, because the mean of its divisors is an integer number (3100680).

Almost surely, 2^18181131 is an apocalyptic number.

18181131 is a deficient number, since it is larger than the sum of its proper divisors (6624309).

18181131 is a wasteful number, since it uses less digits than its factorization.

18181131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140985.

The product of its digits is 192, while the sum is 24.

The square root of 18181131 is about 4263.9337471401. The cubic root of 18181131 is about 262.9502766142.

The spelling of 18181131 in words is "eighteen million, one hundred eighty-one thousand, one hundred thirty-one".