78639424 has 14 divisors (see below), whose sum is σ = 156050234. Its totient is φ = 39319680.

The previous prime is 78639419. The next prime is 78639437. The reversal of 78639424 is 42493687.

It can be written as a sum of positive squares in only one way, i.e., 51265600 + 27373824 = 7160^2 + 5232^2 .

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 614307 + ... + 614434.

Almost surely, 2^78639424 is an apocalyptic number.

It is an amenable number.

78639424 is a deficient number, since it is larger than the sum of its proper divisors (77410810).

78639424 is a wasteful number, since it uses less digits than its factorization.

78639424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1228753 (or 1228743 counting only the distinct ones).

The product of its digits is 290304, while the sum is 43.

The square root of 78639424 is about 8867.8872342853. The cubic root of 78639424 is about 428.4302309039.

The spelling of 78639424 in words is "seventy-eight million, six hundred thirty-nine thousand, four hundred twenty-four".