1321441021 has 4 divisors (see below), whose sum is σ = 1322351932. Its totient is φ = 1320530112.

The previous prime is 1321441019. The next prime is 1321441063. The reversal of 1321441021 is 1201441231.

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 757900900 + 563540121 = 27530^2 + 23739^2 .

It is a cyclic number.

It is not a de Polignac number, because 1321441021 - 2¹ = 1321441019 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1321441021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321441081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 453276 + ... + 456181.

It is an arithmetic number, because the mean of its divisors is an integer number (330587983).

Almost surely, 2^1321441021 is an apocalyptic number.

It is an amenable number.

1321441021 is a deficient number, since it is larger than the sum of its proper divisors (910911).

1321441021 is an equidigital number, since it uses as much as digits as its factorization.

1321441021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 910910.

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 1321441021 is about 36351.6302385464. The cubic root of 1321441021 is about 1097.3603431657.

Adding to 1321441021 its reverse (1201441231), we get a palindrome (2522882252).

The spelling of 1321441021 in words is "one billion, three hundred twenty-one million, four hundred forty-one thousand, twenty-one".