18227312 has 40 divisors (see below), whose sum is σ = 36909840. Its totient is φ = 8709120.

The previous prime is 18227311. The next prime is 18227317. The reversal of 18227312 is 21372281.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18227311) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 75512 + ... + 75752.

It is an arithmetic number, because the mean of its divisors is an integer number (922746).

Almost surely, 2^18227312 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18227312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18454920).

18227312 is an abundant number, since it is smaller than the sum of its proper divisors (18682528).

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

18227312 is a wasteful number, since it uses less digits than its factorization.

18227312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 441 (or 435 counting only the distinct ones).

The product of its digits is 1344, while the sum is 26.

The square root of 18227312 is about 4269.3456173048. The cubic root of 18227312 is about 263.1727240822.

Adding to 18227312 its reverse (21372281), we get a palindrome (39599593).

The spelling of 18227312 in words is "eighteen million, two hundred twenty-seven thousand, three hundred twelve".