78709417 has 2 divisors, whose sum is σ = 78709418. Its totient is φ = 78709416.

The previous prime is 78709387. The next prime is 78709429. The reversal of 78709417 is 71490787.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 63059481 + 15649936 = 7941^2 + 3956^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78709417 is a prime.

It is not a weakly prime, because it can be changed into another prime (78709447) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39354708 + 39354709.

It is an arithmetic number, because the mean of its divisors is an integer number (39354709).

Almost surely, 2^78709417 is an apocalyptic number.

It is an amenable number.

78709417 is a deficient number, since it is larger than the sum of its proper divisors (1).

78709417 is an equidigital number, since it uses as much as digits as its factorization.

78709417 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 98784, while the sum is 43.

The square root of 78709417 is about 8871.8327869725. The cubic root of 78709417 is about 428.5573012856.

The spelling of 78709417 in words is "seventy-eight million, seven hundred nine thousand, four hundred seventeen".