18128331 has 12 divisors (see below), whose sum is σ = 28199808. Its totient is φ = 11155824.

The previous prime is 18128329. The next prime is 18128333. The reversal of 18128331 is 13382181.

It is an interprime number because it is at equal distance from previous prime (18128329) and next prime (18128333).

It is not a de Polignac number, because 18128331 - 2¹ = 18128329 is a prime.

It is a super-2 number, since 2×18128331² = 657272769691122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18128295 and 18128304.

It is not an unprimeable number, because it can be changed into a prime (18128333) 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 11 ways as a sum of consecutive naturals, for example, 77355 + ... + 77588.

It is an arithmetic number, because the mean of its divisors is an integer number (2349984).

Almost surely, 2^18128331 is an apocalyptic number.

18128331 is a deficient number, since it is larger than the sum of its proper divisors (10071477).

18128331 is a wasteful number, since it uses less digits than its factorization.

18128331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154962 (or 154959 counting only the distinct ones).

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

The square root of 18128331 is about 4257.7377796196. The cubic root of 18128331 is about 262.6954843182.

The spelling of 18128331 in words is "eighteen million, one hundred twenty-eight thousand, three hundred thirty-one".