78904109 has 4 divisors (see below), whose sum is σ = 79218720. Its totient is φ = 78589500.

The previous prime is 78904081. The next prime is 78904127. The reversal of 78904109 is 90140987.

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, and also an emirpimes, since its reverse is a distinct semiprime: 90140987 = 17 ⋅5302411.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78904109 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78904139) 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, 156929 + ... + 157430.

It is an arithmetic number, because the mean of its divisors is an integer number (19804680).

Almost surely, 2^78904109 is an apocalyptic number.

It is an amenable number.

78904109 is a deficient number, since it is larger than the sum of its proper divisors (314611).

78904109 is a wasteful number, since it uses less digits than its factorization.

78904109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 314610.

The product of its (nonzero) digits is 18144, while the sum is 38.

The square root of 78904109 is about 8882.7984892150. The cubic root of 78904109 is about 428.9103635604.

The spelling of 78904109 in words is "seventy-eight million, nine hundred four thousand, one hundred nine".