78981439 has 4 divisors (see below), whose sum is σ = 83627424. Its totient is φ = 74335456.

The previous prime is 78981433. The next prime is 78981443. The reversal of 78981439 is 93418987.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93418987 = 181 ⋅516127.

It is a cyclic number.

It is not a de Polignac number, because 78981439 - 2⁵ = 78981407 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 78981392 and 78981401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78981433) 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, 2322967 + ... + 2323000.

It is an arithmetic number, because the mean of its divisors is an integer number (20906856).

Almost surely, 2^78981439 is an apocalyptic number.

78981439 is a deficient number, since it is larger than the sum of its proper divisors (4645985).

78981439 is a wasteful number, since it uses less digits than its factorization.

78981439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4645984.

The product of its digits is 435456, while the sum is 49.

The square root of 78981439 is about 8887.1502181520. The cubic root of 78981439 is about 429.0504357291.

It can be divided in two parts, 789 and 81439, that added together give a palindrome (82228).

The spelling of 78981439 in words is "seventy-eight million, nine hundred eighty-one thousand, four hundred thirty-nine".