18178272 has 144 divisors (see below), whose sum is σ = 60383232. Its totient is φ = 5080320.

The previous prime is 18178271. The next prime is 18178319. The reversal of 18178272 is 27287181.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (144).

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

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18178271) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 143073 + ... + 143199.

It is an arithmetic number, because the mean of its divisors is an integer number (419328).

Almost surely, 2^18178272 is an apocalyptic number.

18178272 is a gapful number since it is divisible by the number (12) 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 18178272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30191616).

18178272 is an abundant number, since it is smaller than the sum of its proper divisors (42204960).

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

18178272 is a wasteful number, since it uses less digits than its factorization.

18178272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221 (or 210 counting only the distinct ones).

The product of its digits is 12544, while the sum is 36.

The square root of 18178272 is about 4263.5984801573. The cubic root of 18178272 is about 262.9364928320.

The spelling of 18178272 in words is "eighteen million, one hundred seventy-eight thousand, two hundred seventy-two".