1100820 has 48 divisors (see below), whose sum is σ = 3523968. Its totient is φ = 251520.

The previous prime is 1100807. The next prime is 1100831. The reversal of 1100820 is 280011.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 1100796 and 1100805.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 891 + ... + 1730.

It is an arithmetic number, because the mean of its divisors is an integer number (73416).

2^1100820 is an apocalyptic number.

1100820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1100820 is an abundant number, since it is smaller than the sum of its proper divisors (2423148).

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

1100820 is a wasteful number, since it uses less digits than its factorization.

1100820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2640 (or 2638 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 1100820 is about 1049.1996950057. The cubic root of 1100820 is about 103.2536557713.

Adding to 1100820 its reverse (280011), we get a palindrome (1380831).

The spelling of 1100820 in words is "one million, one hundred thousand, eight hundred twenty".