1800900 has 144 divisors (see below), whose sum is σ = 6249600. Its totient is φ = 443520.

The previous prime is 1800889. The next prime is 1800907. The reversal of 1800900 is 90081.

1800900 = T₁₁₅ + T₁₁₆ + ... + T₂₃₀.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (1800907) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 62086 + ... + 62114.

It is an arithmetic number, because the mean of its divisors is an integer number (43400).

2^1800900 is an apocalyptic number.

1800900 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 1800900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3124800).

1800900 is an abundant number, since it is smaller than the sum of its proper divisors (4448700).

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

1800900 is a wasteful number, since it uses less digits than its factorization.

1800900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75 (or 62 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The square root of 1800900 is about 1341.9761547807. The cubic root of 1800900 is about 121.6643105401.

Adding to 1800900 its reverse (90081), we get a palindrome (1890981).

The spelling of 1800900 in words is "one million, eight hundred thousand, nine hundred".