1121820 has 48 divisors (see below), whose sum is σ = 3591168. Its totient is φ = 256320.

The previous prime is 1121819. The next prime is 1121831. The reversal of 1121820 is 281211.

It is a super-2 number, since 2×1121820² = 2516960224800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 1121820.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 916 + ... + 1755.

It is an arithmetic number, because the mean of its divisors is an integer number (74816).

2^1121820 is an apocalyptic number.

1121820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1121820 is an abundant number, since it is smaller than the sum of its proper divisors (2469348).

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

1121820 is a wasteful number, since it uses less digits than its factorization.

1121820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2690 (or 2688 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

The square root of 1121820 is about 1059.1600445636. The cubic root of 1121820 is about 103.9061036141.

The spelling of 1121820 in words is "one million, one hundred twenty-one thousand, eight hundred twenty".