1331020321 has 4 divisors (see below), whose sum is σ = 1409315652. Its totient is φ = 1252724992.

The previous prime is 1331020303. The next prime is 1331020331. The reversal of 1331020321 is 1230201331.

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 1136027025 + 194993296 = 33705^2 + 13964^2 .

It is a cyclic number.

It is not a de Polignac number, because 1331020321 - 2⁵ = 1331020289 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1331020295 and 1331020304.

It is not an unprimeable number, because it can be changed into a prime (1331020331) 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, 39147640 + ... + 39147673.

It is an arithmetic number, because the mean of its divisors is an integer number (352328913).

Almost surely, 2^1331020321 is an apocalyptic number.

It is an amenable number.

1331020321 is a deficient number, since it is larger than the sum of its proper divisors (78295331).

1331020321 is an equidigital number, since it uses as much as digits as its factorization.

1331020321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78295330.

The product of its (nonzero) digits is 108, while the sum is 16.

The square root of 1331020321 is about 36483.1511933934. The cubic root of 1331020321 is about 1100.0055980431.

Adding to 1331020321 its reverse (1230201331), we get a palindrome (2561221652).

The spelling of 1331020321 in words is "one billion, three hundred thirty-one million, twenty thousand, three hundred twenty-one".