78789 has 4 divisors (see below), whose sum is σ = 105056. Its totient is φ = 52524.

The previous prime is 78787. The next prime is 78791. The reversal of 78789 is 98787.

78789 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

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 an interprime number because it is at equal distance from previous prime (78787) and next prime (78791).

It is not a de Polignac number, because 78789 - 2¹ = 78787 is a prime.

It is a D-number.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78781) 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, 13129 + ... + 13134.

It is an arithmetic number, because the mean of its divisors is an integer number (26264).

2⁷⁸⁷⁸⁹ is an apocalyptic number.

It is an amenable number.

78789 is a deficient number, since it is larger than the sum of its proper divisors (26267).

78789 is a wasteful number, since it uses less digits than its factorization.

78789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26266.

The product of its digits is 28224, while the sum is 39.

The square root of 78789 is about 280.6937833298. The cubic root of 78789 is about 42.8701690562.

It can be divided in two parts, 7878 and 9, that added together give a palindrome (7887).

The spelling of 78789 in words is "seventy-eight thousand, seven hundred eighty-nine".