1800008500 has 24 divisors (see below), whose sum is σ = 3931219656. Its totient is φ = 720003200.

The previous prime is 1800008489. The next prime is 1800008519. The reversal of 1800008500 is 58000081.

It can be written as a sum of positive squares in 4 ways, for example, as 213101604 + 1586906896 = 14598^2 + 39836^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1799509 + ... + 1800508.

It is an arithmetic number, because the mean of its divisors is an integer number (163800819).

Almost surely, 2^1800008500 is an apocalyptic number.

1800008500 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1800008500 is an abundant number, since it is smaller than the sum of its proper divisors (2131211156).

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

1800008500 is a wasteful number, since it uses less digits than its factorization.

1800008500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3600036 (or 3600024 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 22.

The square root of 1800008500 is about 42426.5070445353. The cubic root of 1800008500 is about 1216.4423138790.

Adding to 1800008500 its reverse (58000081), we get a palindrome (1858008581).

The spelling of 1800008500 in words is "one billion, eight hundred million, eight thousand, five hundred".