78739613 has 2 divisors, whose sum is σ = 78739614. Its totient is φ = 78739612.

The previous prime is 78739567. The next prime is 78739637. The reversal of 78739613 is 31693787.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 73908409 + 4831204 = 8597^2 + 2198^2 .

It is an emirp because it is prime and its reverse (31693787) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78739613 - 2⁸ = 78739357 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78739013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39369806 + 39369807.

It is an arithmetic number, because the mean of its divisors is an integer number (39369807).

Almost surely, 2^78739613 is an apocalyptic number.

It is an amenable number.

78739613 is a deficient number, since it is larger than the sum of its proper divisors (1).

78739613 is an equidigital number, since it uses as much as digits as its factorization.

78739613 is an evil number, because the sum of its binary digits is even.

The product of its digits is 190512, while the sum is 44.

The square root of 78739613 is about 8873.5344142005. The cubic root of 78739613 is about 428.6120980400.

The spelling of 78739613 in words is "seventy-eight million, seven hundred thirty-nine thousand, six hundred thirteen".