1320221209 has 2 divisors, whose sum is σ = 1320221210. Its totient is φ = 1320221208.

The previous prime is 1320221179. The next prime is 1320221233. The reversal of 1320221209 is 9021220231.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1205131225 + 115089984 = 34715^2 + 10728^2 .

It is a cyclic number.

It is not a de Polignac number, because 1320221209 - 2¹³ = 1320213017 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1320221209.

It is not a weakly prime, because it can be changed into another prime (1320221239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660110604 + 660110605.

It is an arithmetic number, because the mean of its divisors is an integer number (660110605).

Almost surely, 2^1320221209 is an apocalyptic number.

It is an amenable number.

1320221209 is a deficient number, since it is larger than the sum of its proper divisors (1).

1320221209 is an equidigital number, since it uses as much as digits as its factorization.

1320221209 is an evil number, because the sum of its binary digits is even.

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

The square root of 1320221209 is about 36334.8484103071. The cubic root of 1320221209 is about 1097.0225842645.

The spelling of 1320221209 in words is "one billion, three hundred twenty million, two hundred twenty-one thousand, two hundred nine".