768515309 has 2 divisors, whose sum is σ = 768515310. Its totient is φ = 768515308.

The previous prime is 768515273. The next prime is 768515347. The reversal of 768515309 is 903515867.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 628755625 + 139759684 = 25075^2 + 11822^2 .

It is an emirp because it is prime and its reverse (903515867) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 768515309 - 2⁸ = 768515053 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 768515309.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (768515609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 384257654 + 384257655.

It is an arithmetic number, because the mean of its divisors is an integer number (384257655).

Almost surely, 2^768515309 is an apocalyptic number.

It is an amenable number.

768515309 is a deficient number, since it is larger than the sum of its proper divisors (1).

768515309 is an equidigital number, since it uses as much as digits as its factorization.

768515309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 226800, while the sum is 44.

The square root of 768515309 is about 27722.1086679928. The cubic root of 768515309 is about 915.9761682332.

The spelling of 768515309 in words is "seven hundred sixty-eight million, five hundred fifteen thousand, three hundred nine".