18208400 has 90 divisors (see below), whose sum is σ = 50942610. Its totient is φ = 6236160.

The previous prime is 18208391. The next prime is 18208409. The reversal of 18208400 is 480281.

It is an interprime number because it is at equal distance from previous prime (18208391) and next prime (18208409).

It can be written as a sum of positive squares in 3 ways, for example, as 94864 + 18113536 = 308^2 + 4256^2 .

It is not an unprimeable number, because it can be changed into a prime (18208409) 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 17 ways as a sum of consecutive naturals, for example, 19136 + ... + 20064.

It is an arithmetic number, because the mean of its divisors is an integer number (566029).

Almost surely, 2^18208400 is an apocalyptic number.

18208400 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 18208400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25471305).

18208400 is an abundant number, since it is smaller than the sum of its proper divisors (32734210).

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

18208400 is a wasteful number, since it uses less digits than its factorization.

18208400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 961 (or 943 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 23.

The square root of 18208400 is about 4267.1301831559. The cubic root of 18208400 is about 263.0816730830.

Adding to 18208400 its reverse (480281), we get a palindrome (18688681).

The spelling of 18208400 in words is "eighteen million, two hundred eight thousand, four hundred".