78759509 has 2 divisors, whose sum is σ = 78759510. Its totient is φ = 78759508.

The previous prime is 78759469. The next prime is 78759511. The reversal of 78759509 is 90595787.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 41280625 + 37478884 = 6425^2 + 6122^2 .

It is a cyclic number.

It is not a de Polignac number, because 78759509 - 2¹⁶ = 78693973 is a prime.

Together with 78759511, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78759559) 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, 39379754 + 39379755.

It is an arithmetic number, because the mean of its divisors is an integer number (39379755).

Almost surely, 2^78759509 is an apocalyptic number.

It is an amenable number.

78759509 is a deficient number, since it is larger than the sum of its proper divisors (1).

78759509 is an equidigital number, since it uses as much as digits as its factorization.

78759509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 793800, while the sum is 50.

The square root of 78759509 is about 8874.6554299308. The cubic root of 78759509 is about 428.6481957034.

The spelling of 78759509 in words is "seventy-eight million, seven hundred fifty-nine thousand, five hundred nine".