78013709 has 2 divisors, whose sum is σ = 78013710. Its totient is φ = 78013708.

The previous prime is 78013703. The next prime is 78013711. The reversal of 78013709 is 90731087.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 75307684 + 2706025 = 8678^2 + 1645^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78013709 is a prime.

It is a super-3 number, since 3×78013709³ (a number of 25 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

Together with 78013711, 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 (78013703) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39006854 + 39006855.

It is an arithmetic number, because the mean of its divisors is an integer number (39006855).

Almost surely, 2^78013709 is an apocalyptic number.

It is an amenable number.

78013709 is a deficient number, since it is larger than the sum of its proper divisors (1).

78013709 is an equidigital number, since it uses as much as digits as its factorization.

78013709 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10584, while the sum is 35.

The square root of 78013709 is about 8832.5369515219. The cubic root of 78013709 is about 427.2908982752.

The spelling of 78013709 in words is "seventy-eight million, thirteen thousand, seven hundred nine".