78824779 has 4 divisors (see below), whose sum is σ = 85990680. Its totient is φ = 71658880.

The previous prime is 78824771. The next prime is 78824783. The reversal of 78824779 is 97742887.

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: 97742887 = 11 ⋅8885717.

It is a cyclic number.

It is not a de Polignac number, because 78824779 - 2³ = 78824771 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78824771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3582934 + ... + 3582955.

It is an arithmetic number, because the mean of its divisors is an integer number (21497670).

Almost surely, 2^78824779 is an apocalyptic number.

78824779 is a deficient number, since it is larger than the sum of its proper divisors (7165901).

78824779 is a wasteful number, since it uses less digits than its factorization.

78824779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7165900.

The product of its digits is 1580544, while the sum is 52.

The square root of 78824779 is about 8878.3319942431. The cubic root of 78824779 is about 428.7665735475.

The spelling of 78824779 in words is "seventy-eight million, eight hundred twenty-four thousand, seven hundred seventy-nine".