18236220 has 24 divisors (see below), whose sum is σ = 51061584. Its totient is φ = 4862976.

The previous prime is 18236213. The next prime is 18236221. The reversal of 18236220 is 2263281.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18236221) 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 7 ways as a sum of consecutive naturals, for example, 151909 + ... + 152028.

It is an arithmetic number, because the mean of its divisors is an integer number (2127566).

Almost surely, 2^18236220 is an apocalyptic number.

18236220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18236220 is an abundant number, since it is smaller than the sum of its proper divisors (32825364).

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

18236220 is a wasteful number, since it uses less digits than its factorization.

18236220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 303949 (or 303947 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 18236220 is about 4270.3887410867. The cubic root of 18236220 is about 263.2155894413.

The spelling of 18236220 in words is "eighteen million, two hundred thirty-six thousand, two hundred twenty".