1819998800 has 90 divisors (see below), whose sum is σ = 4470304842. Its totient is φ = 711825920.

The previous prime is 1819998781. The next prime is 1819998893. The reversal of 1819998800 is 88999181.

It can be written as a sum of positive squares in 9 ways, for example, as 31047184 + 1788951616 = 5572^2 + 42296^2 .

It is a Harshad number since it is a multiple of its sum of digits (53).

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 17 ways as a sum of consecutive naturals, for example, 6211454 + ... + 6211746.

Almost surely, 2^1819998800 is an apocalyptic number.

1819998800 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 1819998800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2235152421).

1819998800 is an abundant number, since it is smaller than the sum of its proper divisors (2650306042).

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

1819998800 is an equidigital number, since it uses as much as digits as its factorization.

1819998800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 657 (or 353 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 53.

The square root of 1819998800 is about 42661.4439511838. The cubic root of 1819998800 is about 1220.9288814107.

Multiplying 1819998800 by its sum of digits (53), we get a square (96459936400 = 310580²).

1819998800 divided by its sum of digits (53) gives a square (34339600 = 5860²).

The spelling of 1819998800 in words is "one billion, eight hundred nineteen million, nine hundred ninety-eight thousand, eight hundred".