78074809 has 2 divisors, whose sum is σ = 78074810. Its totient is φ = 78074808.

The previous prime is 78074803. The next prime is 78074827. The reversal of 78074809 is 90847087.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 75342400 + 2732409 = 8680^2 + 1653^2 .

It is a cyclic number.

It is not a de Polignac number, because 78074809 - 2⁷ = 78074681 is a prime.

It is not a weakly prime, because it can be changed into another prime (78074803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39037404 + 39037405.

It is an arithmetic number, because the mean of its divisors is an integer number (39037405).

Almost surely, 2^78074809 is an apocalyptic number.

It is an amenable number.

78074809 is a deficient number, since it is larger than the sum of its proper divisors (1).

78074809 is an equidigital number, since it uses as much as digits as its factorization.

78074809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 112896, while the sum is 43.

The square root of 78074809 is about 8835.9950769565. The cubic root of 78074809 is about 427.4024199613.

The spelling of 78074809 in words is "seventy-eight million, seventy-four thousand, eight hundred nine".