18028188 has 36 divisors (see below), whose sum is σ = 47971560. Its totient is φ = 5692896.

The previous prime is 18028147. The next prime is 18028189. The reversal of 18028188 is 88182081.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18028189) 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 11 ways as a sum of consecutive naturals, for example, 12495 + ... + 13862.

Almost surely, 2^18028188 is an apocalyptic number.

18028188 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

18028188 is an abundant number, since it is smaller than the sum of its proper divisors (29943372).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18028188 is a wasteful number, since it uses less digits than its factorization.

18028188 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26386 (or 26381 counting only the distinct ones).

The product of its (nonzero) digits is 8192, while the sum is 36.

The square root of 18028188 is about 4245.9613752365. The cubic root of 18028188 is about 262.2108707727.

The spelling of 18028188 in words is "eighteen million, twenty-eight thousand, one hundred eighty-eight".