1329020221 has 4 divisors (see below), whose sum is σ = 1359927712. Its totient is φ = 1298112732.

The previous prime is 1329020219. The next prime is 1329020249. The reversal of 1329020221 is 1220209231.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1329020221 - 2¹ = 1329020219 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1329020192 and 1329020201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1329020291) 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, 15453681 + ... + 15453766.

It is an arithmetic number, because the mean of its divisors is an integer number (339981928).

Almost surely, 2^1329020221 is an apocalyptic number.

It is an amenable number.

1329020221 is a deficient number, since it is larger than the sum of its proper divisors (30907491).

1329020221 is an equidigital number, since it uses as much as digits as its factorization.

1329020221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30907490.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 1329020221 is about 36455.7296045491. The cubic root of 1329020221 is about 1099.4543356995.

Adding to 1329020221 its reverse (1220209231), we get a palindrome (2549229452).

The spelling of 1329020221 in words is "one billion, three hundred twenty-nine million, twenty thousand, two hundred twenty-one".