18180399 has 8 divisors (see below), whose sum is σ = 24756480. Its totient is φ = 11862296.

The previous prime is 18180391. The next prime is 18180413. The reversal of 18180399 is 99308181.

It is a happy number.

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 18180399 - 2³ = 18180391 is a prime.

It is a super-3 number, since 3×18180399³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18180391) 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, 64329 + ... + 64610.

It is an arithmetic number, because the mean of its divisors is an integer number (3094560).

Almost surely, 2^18180399 is an apocalyptic number.

18180399 is a deficient number, since it is larger than the sum of its proper divisors (6576081).

18180399 is a wasteful number, since it uses less digits than its factorization.

18180399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128989.

The product of its (nonzero) digits is 15552, while the sum is 39.

The square root of 18180399 is about 4263.8479100456. The cubic root of 18180399 is about 262.9467476408.

The spelling of 18180399 in words is "eighteen million, one hundred eighty thousand, three hundred ninety-nine".