78992909 has 2 divisors, whose sum is σ = 78992910. Its totient is φ = 78992908.

The previous prime is 78992887. The next prime is 78992911. The reversal of 78992909 is 90929987.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51984100 + 27008809 = 7210^2 + 5197^2 .

It is an emirp because it is prime and its reverse (90929987) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78992909 - 2²⁰ = 77944333 is a prime.

Together with 78992911, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78992009) 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, 39496454 + 39496455.

It is an arithmetic number, because the mean of its divisors is an integer number (39496455).

Almost surely, 2^78992909 is an apocalyptic number.

It is an amenable number.

78992909 is a deficient number, since it is larger than the sum of its proper divisors (1).

78992909 is an equidigital number, since it uses as much as digits as its factorization.

78992909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 734832, while the sum is 53.

The square root of 78992909 is about 8887.7955084487. The cubic root of 78992909 is about 429.0712041963.

The spelling of 78992909 in words is "seventy-eight million, nine hundred ninety-two thousand, nine hundred nine".