18132381 has 6 divisors (see below), whose sum is σ = 26191230. Its totient is φ = 12088248.

The previous prime is 18132377. The next prime is 18132391. The reversal of 18132381 is 18323181.

It can be written as a sum of positive squares in only one way, i.e., 9400356 + 8732025 = 3066^2 + 2955^2 .

It is not a de Polignac number, because 18132381 - 2² = 18132377 is a prime.

It is a super-2 number, since 2×18132381² = 657566481458322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18132371) 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 5 ways as a sum of consecutive naturals, for example, 1007346 + ... + 1007363.

It is an arithmetic number, because the mean of its divisors is an integer number (4365205).

Almost surely, 2^18132381 is an apocalyptic number.

It is an amenable number.

18132381 is a deficient number, since it is larger than the sum of its proper divisors (8058849).

18132381 is a wasteful number, since it uses less digits than its factorization.

18132381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2014715 (or 2014712 counting only the distinct ones).

The product of its digits is 1152, while the sum is 27.

The square root of 18132381 is about 4258.2133577358. The cubic root of 18132381 is about 262.7150455507.

The spelling of 18132381 in words is "eighteen million, one hundred thirty-two thousand, three hundred eighty-one".