18281000 has 64 divisors (see below), whose sum is σ = 43439760. Its totient is φ = 7200000.

The previous prime is 18280993. The next prime is 18281023. The reversal of 18281000 is 18281.

It can be written as a sum of positive squares in 8 ways, for example, as 320356 + 17960644 = 566^2 + 4238^2 .

It is a super-2 number, since 2×18281000² = 668389922000000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

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 15 ways as a sum of consecutive naturals, for example, 100910 + ... + 101090.

Almost surely, 2^18281000 is an apocalyptic number.

18281000 is a gapful number since it is divisible by the number (10) 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 18281000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21719880).

18281000 is an abundant number, since it is smaller than the sum of its proper divisors (25158760).

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

18281000 is a wasteful number, since it uses less digits than its factorization.

18281000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 303 (or 289 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 20.

The square root of 18281000 is about 4275.6286087545. The cubic root of 18281000 is about 263.4308599220.

Adding to 18281000 its reverse (18281), we get a palindrome (18299281).

18281000 divided by its reverse (18281) gives a cube (1000 = 10³).

The spelling of 18281000 in words is "eighteen million, two hundred eighty-one thousand".