18500000 has 84 divisors (see below), whose sum is σ = 46757214. Its totient is φ = 7200000.

The previous prime is 18499931. The next prime is 18500017. The reversal of 18500000 is 581.

It can be written as a sum of positive squares in 7 ways, for example, as 5740816 + 12759184 = 2396^2 + 3572^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 499982 + ... + 500018.

Almost surely, 2^18500000 is an apocalyptic number.

18500000 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 18500000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23378607).

18500000 is an abundant number, since it is smaller than the sum of its proper divisors (28257214).

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

18500000 is an frugal number, since it uses more digits than its factorization.

18500000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77 (or 44 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 14.

The square root of 18500000 is about 4301.1626335213. The cubic root of 18500000 is about 264.4786236347.

Adding to 18500000 its reverse (581), we get a palindrome (18500581).

It can be divided in two parts, 18 and 500000, that multiplied together give a square (9000000 = 3000²).

The spelling of 18500000 in words is "eighteen million, five hundred thousand".