1329716221 has 4 divisors (see below), whose sum is σ = 1330111744. Its totient is φ = 1329320700.

The previous prime is 1329716189. The next prime is 1329716231. The reversal of 1329716221 is 1226179231.

It is a happy number.

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 1329716221 - 2⁵ = 1329716189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1329716231) 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, 192675 + ... + 199456.

It is an arithmetic number, because the mean of its divisors is an integer number (332527936).

Almost surely, 2^1329716221 is an apocalyptic number.

It is an amenable number.

1329716221 is a deficient number, since it is larger than the sum of its proper divisors (395523).

1329716221 is an equidigital number, since it uses as much as digits as its factorization.

1329716221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 395522.

The product of its digits is 9072, while the sum is 34.

The square root of 1329716221 is about 36465.2741796905. The cubic root of 1329716221 is about 1099.6462281086.

The spelling of 1329716221 in words is "one billion, three hundred twenty-nine million, seven hundred sixteen thousand, two hundred twenty-one".