247309 has 2 divisors, whose sum is σ = 247310. Its totient is φ = 247308.

The previous prime is 247301. The next prime is 247337. The reversal of 247309 is 903742.

247309 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 198025 + 49284 = 445^2 + 222^2 .

It is a cyclic number.

It is not a de Polignac number, because 247309 - 2³ = 247301 is a prime.

It is a super-2 number, since 2×247309² = 122323482962, which contains 22 as substring.

247309 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (247301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 123654 + 123655.

It is an arithmetic number, because the mean of its divisors is an integer number (123655).

2²⁴⁷³⁰⁹ is an apocalyptic number.

It is an amenable number.

247309 is a deficient number, since it is larger than the sum of its proper divisors (1).

247309 is an equidigital number, since it uses as much as digits as its factorization.

247309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1512, while the sum is 25.

The square root of 247309 is about 497.3017192812. The cubic root of 247309 is about 62.7692067785.

The spelling of 247309 in words is "two hundred forty-seven thousand, three hundred nine".