220400309 has 2 divisors, whose sum is σ = 220400310. Its totient is φ = 220400308.

The previous prime is 220400293. The next prime is 220400317. The reversal of 220400309 is 903004022.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 179158225 + 41242084 = 13385^2 + 6422^2 .

It is a cyclic number.

It is not a de Polignac number, because 220400309 - 2⁴ = 220400293 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (220400809) 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, 110200154 + 110200155.

It is an arithmetic number, because the mean of its divisors is an integer number (110200155).

Almost surely, 2^220400309 is an apocalyptic number.

It is an amenable number.

220400309 is a deficient number, since it is larger than the sum of its proper divisors (1).

220400309 is an equidigital number, since it uses as much as digits as its factorization.

220400309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 220400309 is about 14845.8852548442. The cubic root of 220400309 is about 604.0470017734.

The spelling of 220400309 in words is "two hundred twenty million, four hundred thousand, three hundred nine".