220765409 has 2 divisors, whose sum is σ = 220765410. Its totient is φ = 220765408.

The previous prime is 220765373. The next prime is 220765411. The reversal of 220765409 is 904567022.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 216237025 + 4528384 = 14705^2 + 2128^2 .

It is a cyclic number.

It is not a de Polignac number, because 220765409 - 2¹⁶ = 220699873 is a prime.

It is a Sophie Germain prime.

Together with 220765411, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (220765609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110382704 + 110382705.

It is an arithmetic number, because the mean of its divisors is an integer number (110382705).

Almost surely, 2^220765409 is an apocalyptic number.

It is an amenable number.

220765409 is a deficient number, since it is larger than the sum of its proper divisors (1).

220765409 is an equidigital number, since it uses as much as digits as its factorization.

220765409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 30240, while the sum is 35.

The square root of 220765409 is about 14858.1765031918. The cubic root of 220765409 is about 604.3803586813.

The spelling of 220765409 in words is "two hundred twenty million, seven hundred sixty-five thousand, four hundred nine".