1800306 has 20 divisors (see below), whose sum is σ = 4034382.
Its totient is φ = 600048.
The previous prime is 1800301. The next prime is 1800311. The reversal of 1800306 is 6030081.
It is an interprime number because it is at equal distance from previous prime (1800301) and next prime (1800311).
It can be written as a sum of positive squares in only one way, i.e., 1798281 + 2025 = 1341^2 + 45^2
It is a super-2 number, since 2×18003062 = 6482203387272, which contains 22 as substring.
It is a Harshad number since it is a multiple of its sum of digits (18).
It is a Curzon number.
It is not an unprimeable number, because it can be changed into a prime (1800301) by changing a digit.
It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 5395 + ... + 5718.
21800306 is an apocalyptic number.
1800306 is an abundant number, since it is smaller than the sum of its proper divisors (2234076).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
1800306 is a wasteful number, since it uses less digits than its factorization.
1800306 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 11127 (or 11118 counting only the distinct ones).
The product of its (nonzero) digits is 144, while the sum is 18.
The square root of 1800306 is about 1341.7548211205.
The cubic root of 1800306 is about 121.6509326832.
Adding to 1800306 its reverse (6030081), we get a palindrome (7830387).
The spelling of 1800306 in words is "one million, eight hundred thousand, three hundred six".