78508139 has 2 divisors, whose sum is σ = 78508140. Its totient is φ = 78508138.

The previous prime is 78508109. The next prime is 78508141. The reversal of 78508139 is 93180587.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 78508139 - 2⁸ = 78507883 is a prime.

Together with 78508141, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 78508096 and 78508105.

It is not a weakly prime, because it can be changed into another prime (78508109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39254069 + 39254070.

It is an arithmetic number, because the mean of its divisors is an integer number (39254070).

Almost surely, 2^78508139 is an apocalyptic number.

78508139 is a deficient number, since it is larger than the sum of its proper divisors (1).

78508139 is an equidigital number, since it uses as much as digits as its factorization.

78508139 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 60480, while the sum is 41.

The square root of 78508139 is about 8860.4818717720. The cubic root of 78508139 is about 428.1916830722.

The spelling of 78508139 in words is "seventy-eight million, five hundred eight thousand, one hundred thirty-nine".