78239 has 4 divisors (see below), whose sum is σ = 89424. Its totient is φ = 67056.

The previous prime is 78233. The next prime is 78241. The reversal of 78239 is 93287.

78239 = T₁₄₆ + T₁₄₇ + ... + T₁₅₂.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 78239 - 2⁸ = 77983 is a prime.

It is a super-2 number, since 2×78239² = 12242682242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78233) 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, 5582 + ... + 5595.

It is an arithmetic number, because the mean of its divisors is an integer number (22356).

2⁷⁸²³⁹ is an apocalyptic number.

78239 is a deficient number, since it is larger than the sum of its proper divisors (11185).

78239 is a wasteful number, since it uses less digits than its factorization.

78239 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11184.

The product of its digits is 3024, while the sum is 29.

The square root of 78239 is about 279.7123522478. The cubic root of 78239 is about 42.7701818688.

Subtracting from 78239 its sum of digits (29), we obtain a triangular number (78210 = T₃₉₅).

It can be divided in two parts, 7823 and 9, that multiplied together give a palindrome (70407).

The spelling of 78239 in words is "seventy-eight thousand, two hundred thirty-nine".