1081921 has 4 divisors (see below), whose sum is σ = 1085652. Its totient is φ = 1078192.

The previous prime is 1081919. The next prime is 1081937. The reversal of 1081921 is 1291801.

1081921 = 735² + 736².

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 540225 + 541696 = 735^2 + 736^2 .

It is a cyclic number.

It is not a de Polignac number, because 1081921 - 2¹ = 1081919 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

1081921 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 1081892 and 1081901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1081901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1390 + ... + 2023.

It is an arithmetic number, because the mean of its divisors is an integer number (271413).

2^1081921 is an apocalyptic number.

1081921 is the 736-th centered square number.

It is an amenable number.

1081921 is a deficient number, since it is larger than the sum of its proper divisors (3731).

1081921 is an equidigital number, since it uses as much as digits as its factorization.

1081921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3730.

The product of its (nonzero) digits is 144, while the sum is 22.

The square root of 1081921 is about 1040.1543154744. The cubic root of 1081921 is about 102.6593515805.

It can be divided in two parts, 1081 and 921, that added together give a palindrome (2002).

The spelling of 1081921 in words is "one million, eighty-one thousand, nine hundred twenty-one".