1081800 has 72 divisors (see below), whose sum is σ = 3639090. Its totient is φ = 288000.
The previous prime is 1081793. The next prime is 1081813. The reversal of 1081800 is 81801.
1081800 = 583 + 593 + ... + 623.
It is a happy number.
It can be written as a sum of positive squares in 3 ways, for example, as 956484 + 125316 = 978^2 + 354^2 .
It is a tau number, because it is divible by the number of its divisors (72).
It is a Harshad number since it is a multiple of its sum of digits (18).
It is an unprimeable number.
It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1500 + ... + 2100.
21081800 is an apocalyptic number.
1081800 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 1081800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1819545).
1081800 is an abundant number, since it is smaller than the sum of its proper divisors (2557290).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
1081800 is a wasteful number, since it uses less digits than its factorization.
1081800 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 623 (or 611 counting only the distinct ones).
The product of its (nonzero) digits is 64, while the sum is 18.
The square root of 1081800 is about 1040.0961494016. The cubic root of 1081800 is about 102.6555243619.
Subtracting from 1081800 its reverse (81801), we obtain a palindrome (999999).
It can be divided in two parts, 1081 and 800, that added together give a palindrome (1881).
The spelling of 1081800 in words is "one million, eighty-one thousand, eight hundred".
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