18078228 has 72 divisors (see below), whose sum is σ = 54180672. Its totient is φ = 5163264.

The previous prime is 18078217. The next prime is 18078257. The reversal of 18078228 is 82287081.

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

It is a junction number, because it is equal to n+sod(n) for n = 18078192 and 18078201.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 5476 + ... + 8132.

Almost surely, 2^18078228 is an apocalyptic number.

18078228 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18078228, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27090336).

18078228 is an abundant number, since it is smaller than the sum of its proper divisors (36102444).

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

18078228 is a wasteful number, since it uses less digits than its factorization.

18078228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2683 (or 2669 counting only the distinct ones).

The product of its (nonzero) digits is 14336, while the sum is 36.

The square root of 18078228 is about 4251.8499503157. The cubic root of 18078228 is about 262.4532488170.

The spelling of 18078228 in words is "eighteen million, seventy-eight thousand, two hundred twenty-eight".