1121821 has 4 divisors (see below), whose sum is σ = 1129500. Its totient is φ = 1114144.

The previous prime is 1121819. The next prime is 1121831. The reversal of 1121821 is 1281211.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 240100 + 881721 = 490^2 + 939^2 .

It is a cyclic number.

It is not a de Polignac number, because 1121821 - 2¹ = 1121819 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1121795 and 1121804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1121831) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3616 + ... + 3913.

It is an arithmetic number, because the mean of its divisors is an integer number (282375).

2^1121821 is an apocalyptic number.

It is an amenable number.

1121821 is a deficient number, since it is larger than the sum of its proper divisors (7679).

1121821 is an equidigital number, since it uses as much as digits as its factorization.

1121821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7678.

The product of its digits is 32, while the sum is 16.

The square root of 1121821 is about 1059.1605166357. The cubic root of 1121821 is about 103.9061344883.

The spelling of 1121821 in words is "one million, one hundred twenty-one thousand, eight hundred twenty-one".