220505309 has 2 divisors, whose sum is σ = 220505310. Its totient is φ = 220505308.

The previous prime is 220505293. The next prime is 220505323. The reversal of 220505309 is 903505022.

220505309 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 205836409 + 14668900 = 14347^2 + 3830^2 .

It is a cyclic number.

It is not a de Polignac number, because 220505309 - 2⁴ = 220505293 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (220505809) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110252654 + 110252655.

It is an arithmetic number, because the mean of its divisors is an integer number (110252655).

Almost surely, 2^220505309 is an apocalyptic number.

It is an amenable number.

220505309 is a deficient number, since it is larger than the sum of its proper divisors (1).

220505309 is an equidigital number, since it uses as much as digits as its factorization.

220505309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2700, while the sum is 26.

The square root of 220505309 is about 14849.4211671701. The cubic root of 220505309 is about 604.1429103895.

The spelling of 220505309 in words is "two hundred twenty million, five hundred five thousand, three hundred nine".