78039397 has 2 divisors, whose sum is σ = 78039398. Its totient is φ = 78039396.

The previous prime is 78039337. The next prime is 78039407. The reversal of 78039397 is 79393087.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 56565441 + 21473956 = 7521^2 + 4634^2 .

It is an emirp because it is prime and its reverse (79393087) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78039397 - 2¹⁵ = 78006629 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78039337) 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, 39019698 + 39019699.

It is an arithmetic number, because the mean of its divisors is an integer number (39019699).

Almost surely, 2^78039397 is an apocalyptic number.

It is an amenable number.

78039397 is a deficient number, since it is larger than the sum of its proper divisors (1).

78039397 is an equidigital number, since it uses as much as digits as its factorization.

78039397 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 285768, while the sum is 46.

The square root of 78039397 is about 8833.9910006746. The cubic root of 78039397 is about 427.3377919311.

The spelling of 78039397 in words is "seventy-eight million, thirty-nine thousand, three hundred ninety-seven".