78082391 has 2 divisors, whose sum is σ = 78082392. Its totient is φ = 78082390.

The previous prime is 78082363. The next prime is 78082399. The reversal of 78082391 is 19328087.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 78082391 - 2¹⁴ = 78066007 is a prime.

It is a Sophie Germain 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 (78082399) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39041195 + 39041196.

It is an arithmetic number, because the mean of its divisors is an integer number (39041196).

Almost surely, 2^78082391 is an apocalyptic number.

78082391 is a deficient number, since it is larger than the sum of its proper divisors (1).

78082391 is an equidigital number, since it uses as much as digits as its factorization.

78082391 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24192, while the sum is 38.

The square root of 78082391 is about 8836.4241070696. The cubic root of 78082391 is about 427.4162548131.

The spelling of 78082391 in words is "seventy-eight million, eighty-two thousand, three hundred ninety-one".