1820028 has 48 divisors (see below), whose sum is σ = 4967424.
Its totient is φ = 507840.
The previous prime is 1820023. The next prime is 1820033. The reversal of 1820028 is 8200281.
1820028 divided by its sum of digits (21) gives a palindrome (86668).
It is an interprime number because it is at equal distance from previous prime (1820023) and next prime (1820033).
It is a Harshad number since it is a multiple of its sum of digits (21).
It is a junction number, because it is equal to n+sod(n) for n = 1819986 and 1820013.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (1820023) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (13) of ones.
It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3718 + ... + 4178.
It is an arithmetic number, because the mean of its divisors is an integer number (103488).
21820028 is an apocalyptic number.
It is an amenable number.
It is a practical number, because each smaller number is the sum of distinct divisors of 1820028, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2483712).
1820028 is an abundant number, since it is smaller than the sum of its proper divisors (3147396).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
1820028 is a wasteful number, since it uses less digits than its factorization.
1820028 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 522 (or 520 counting only the distinct ones).
The product of its (nonzero) digits is 256, while the sum is 21.
The square root of 1820028 is about 1349.0841337737.
The cubic root of 1820028 is about 122.0935410890.
The spelling of 1820028 in words is "one million, eight hundred twenty thousand, twenty-eight".