78636009 has 4 divisors (see below), whose sum is σ = 104848016. Its totient is φ = 52424004.

The previous prime is 78635983. The next prime is 78636013. The reversal of 78636009 is 90063687.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 78636009 - 2¹³ = 78627817 is a prime.

It is a super-2 number, since 2×78636009² = 12367243822896162, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (78636209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13105999 + ... + 13106004.

It is an arithmetic number, because the mean of its divisors is an integer number (26212004).

Almost surely, 2^78636009 is an apocalyptic number.

It is an amenable number.

78636009 is a deficient number, since it is larger than the sum of its proper divisors (26212007).

78636009 is a wasteful number, since it uses less digits than its factorization.

78636009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26212006.

The product of its (nonzero) digits is 54432, while the sum is 39.

The square root of 78636009 is about 8867.6946835127. The cubic root of 78636009 is about 428.4240291358.

The spelling of 78636009 in words is "seventy-eight million, six hundred thirty-six thousand, nine".