18198280 has 32 divisors (see below), whose sum is σ = 41068440. Its totient is φ = 7257600.

The previous prime is 18198263. The next prime is 18198287. The reversal of 18198280 is 8289181.

It can be written as a sum of positive squares in 4 ways, for example, as 17355556 + 842724 = 4166^2 + 918^2 .

It is a Smith number, since the sum of its digits (37) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (18198287) 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, 23662 + ... + 24418.

Almost surely, 2^18198280 is an apocalyptic number.

18198280 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18198280 is an abundant number, since it is smaller than the sum of its proper divisors (22870160).

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

18198280 is a wasteful number, since it uses less digits than its factorization.

18198280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1369 (or 1365 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 37.

The square root of 18198280 is about 4265.9442096680. The cubic root of 18198280 is about 263.0329248876.

Subtracting from 18198280 its reverse (8289181), we obtain a palindrome (9909099).

The spelling of 18198280 in words is "eighteen million, one hundred ninety-eight thousand, two hundred eighty".