78999 has 8 divisors (see below), whose sum is σ = 111600. Its totient is φ = 49536.

The previous prime is 78989. The next prime is 79031. The reversal of 78999 is 99987.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 78999 - 2⁹ = 78487 is a prime.

78999 is a modest number, since divided by 999 gives 78 as remainder.

It is a plaindrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 78999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78919) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 724 + ... + 825.

It is an arithmetic number, because the mean of its divisors is an integer number (13950).

2⁷⁸⁹⁹⁹ is an apocalyptic number.

78999 is a deficient number, since it is larger than the sum of its proper divisors (32601).

78999 is a wasteful number, since it uses less digits than its factorization.

78999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1569.

The product of its digits is 40824, while the sum is 42.

The square root of 78999 is about 281.0676075253. The cubic root of 78999 is about 42.9082232214.

It can be divided in two parts, 789 and 99, that added together give a palindrome (888).

The spelling of 78999 in words is "seventy-eight thousand, nine hundred ninety-nine".