18368381 has 8 divisors (see below), whose sum is σ = 19768824. Its totient is φ = 17003520.

The previous prime is 18368359. The next prime is 18368387. The reversal of 18368381 is 18386381.

It can be written as a sum of positive squares in 4 ways, for example, as 4268356 + 14100025 = 2066^2 + 3755^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 18368381 - 2²² = 14174077 is a prime.

It is a super-3 number, since 3×18368381³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18368387) 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 7 ways as a sum of consecutive naturals, for example, 7820 + ... + 9893.

It is an arithmetic number, because the mean of its divisors is an integer number (2471103).

Almost surely, 2^18368381 is an apocalyptic number.

It is an amenable number.

18368381 is a deficient number, since it is larger than the sum of its proper divisors (1400443).

18368381 is a wasteful number, since it uses less digits than its factorization.

18368381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17791.

The product of its digits is 27648, while the sum is 38.

The square root of 18368381 is about 4285.8349244925. The cubic root of 18368381 is about 263.8499156496.

The spelling of 18368381 in words is "eighteen million, three hundred sixty-eight thousand, three hundred eighty-one".