78407969 has 2 divisors, whose sum is σ = 78407970. Its totient is φ = 78407968.

The previous prime is 78407929. The next prime is 78407971. The reversal of 78407969 is 96970487.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59598400 + 18809569 = 7720^2 + 4337^2 .

It is an emirp because it is prime and its reverse (96970487) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78407969 is a prime.

It is a super-4 number, since 4×78407969⁴ (a number of 33 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

Together with 78407971, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (78407929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39203984 + 39203985.

It is an arithmetic number, because the mean of its divisors is an integer number (39203985).

Almost surely, 2^78407969 is an apocalyptic number.

It is an amenable number.

78407969 is a deficient number, since it is larger than the sum of its proper divisors (1).

78407969 is an equidigital number, since it uses as much as digits as its factorization.

78407969 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 762048, while the sum is 50.

The square root of 78407969 is about 8854.8274404417. The cubic root of 78407969 is about 428.0094929766.

The spelling of 78407969 in words is "seventy-eight million, four hundred seven thousand, nine hundred sixty-nine".