78671609 has 4 divisors (see below), whose sum is σ = 82812240. Its totient is φ = 74530980.

The previous prime is 78671591. The next prime is 78671623. The reversal of 78671609 is 90617687.

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 a cyclic number.

It is not a de Polignac number, because 78671609 - 2⁸ = 78671353 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 78671609.

It is not an unprimeable number, because it can be changed into a prime (78671629) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2070287 + ... + 2070324.

It is an arithmetic number, because the mean of its divisors is an integer number (20703060).

Almost surely, 2^78671609 is an apocalyptic number.

It is an amenable number.

78671609 is a deficient number, since it is larger than the sum of its proper divisors (4140631).

78671609 is a wasteful number, since it uses less digits than its factorization.

78671609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4140630.

The product of its (nonzero) digits is 127008, while the sum is 44.

The square root of 78671609 is about 8869.7017424488. The cubic root of 78671609 is about 428.4886712534.

The spelling of 78671609 in words is "seventy-eight million, six hundred seventy-one thousand, six hundred nine".