78633839 has 2 divisors, whose sum is σ = 78633840. Its totient is φ = 78633838.

The previous prime is 78633833. The next prime is 78633847. The reversal of 78633839 is 93833687.

It is a weak prime.

It is an emirp because it is prime and its reverse (93833687) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78633839 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 78633793 and 78633802.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78633833) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39316919 + 39316920.

It is an arithmetic number, because the mean of its divisors is an integer number (39316920).

Almost surely, 2^78633839 is an apocalyptic number.

78633839 is a deficient number, since it is larger than the sum of its proper divisors (1).

78633839 is an equidigital number, since it uses as much as digits as its factorization.

78633839 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 653184, while the sum is 47.

The square root of 78633839 is about 8867.5723284335. The cubic root of 78633839 is about 428.4200882411.

The spelling of 78633839 in words is "seventy-eight million, six hundred thirty-three thousand, eight hundred thirty-nine".