1801999200 has 144 divisors (see below), whose sum is σ = 6008896656. Its totient is φ = 468787200.

The previous prime is 1801999169. The next prime is 1801999207. The reversal of 1801999200 is 29991081.

It is a happy number.

It is a super-2 number, since 2×1801999200² = 6494402233601280000, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1801999207) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 89244 + ... + 107556.

It is an arithmetic number, because the mean of its divisors is an integer number (41728449).

Almost surely, 2^1801999200 is an apocalyptic number.

1801999200 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 1801999200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3004448328).

1801999200 is an abundant number, since it is smaller than the sum of its proper divisors (4206897456).

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

1801999200 is a wasteful number, since it uses less digits than its factorization.

1801999200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18377 (or 18364 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 39.

The square root of 1801999200 is about 42449.9611307243. The cubic root of 1801999200 is about 1216.8905857545.

It can be divided in two parts, 1801 and 999200, that added together give a palindrome (1001001).

The spelling of 1801999200 in words is "one billion, eight hundred one million, nine hundred ninety-nine thousand, two hundred".