678992309 has 2 divisors, whose sum is σ = 678992310. Its totient is φ = 678992308.

The previous prime is 678992299. The next prime is 678992333. The reversal of 678992309 is 903299876.

678992309 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., 511212100 + 167780209 = 22610^2 + 12953^2 .

It is a cyclic number.

It is not a de Polignac number, because 678992309 - 2¹² = 678988213 is a prime.

It is a super-2 number, since 2×678992309² = 922061111362302962, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (678992339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 339496154 + 339496155.

It is an arithmetic number, because the mean of its divisors is an integer number (339496155).

Almost surely, 2^678992309 is an apocalyptic number.

It is an amenable number.

678992309 is a deficient number, since it is larger than the sum of its proper divisors (1).

678992309 is an equidigital number, since it uses as much as digits as its factorization.

678992309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1469664, while the sum is 53.

The square root of 678992309 is about 26057.4808644274. The cubic root of 678992309 is about 878.9313426589.

The spelling of 678992309 in words is "six hundred seventy-eight million, nine hundred ninety-two thousand, three hundred nine".