70309 has 2 divisors, whose sum is σ = 70310. Its totient is φ = 70308.

The previous prime is 70297. The next prime is 70313. The reversal of 70309 is 90307.

70309 = T₂₁₅ + T₂₁₆ + T₂₁₇.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 49284 + 21025 = 222^2 + 145^2 .

It is a cyclic number.

It is not a de Polignac number, because 70309 - 2⁷ = 70181 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (70379) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35154 + 35155.

It is an arithmetic number, because the mean of its divisors is an integer number (35155).

2⁷⁰³⁰⁹ is an apocalyptic number.

70309 is the 217-th centered triangular number.

It is an amenable number.

70309 is a deficient number, since it is larger than the sum of its proper divisors (1).

70309 is an equidigital number, since it uses as much as digits as its factorization.

70309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 189, while the sum is 19.

The square root of 70309 is about 265.1584431995. The cubic root of 70309 is about 41.2734057556.

The spelling of 70309 in words is "seventy thousand, three hundred nine".