78712709 has 2 divisors, whose sum is σ = 78712710. Its totient is φ = 78712708.

The previous prime is 78712681. The next prime is 78712723. The reversal of 78712709 is 90721787.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 69772609 + 8940100 = 8353^2 + 2990^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78712709 is a prime.

It is equal to p_4598663 and since 78712709 and 4598663 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78712789) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39356354 + 39356355.

It is an arithmetic number, because the mean of its divisors is an integer number (39356355).

Almost surely, 2^78712709 is an apocalyptic number.

It is an amenable number.

78712709 is a deficient number, since it is larger than the sum of its proper divisors (1).

78712709 is an equidigital number, since it uses as much as digits as its factorization.

78712709 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 49392, while the sum is 41.

The square root of 78712709 is about 8872.0183160316. The cubic root of 78712709 is about 428.5632759666.

The spelling of 78712709 in words is "seventy-eight million, seven hundred twelve thousand, seven hundred nine".