78424389 has 32 divisors (see below), whose sum is σ = 122777600. Its totient is φ = 49397040.

The previous prime is 78424363. The next prime is 78424391. The reversal of 78424389 is 98342487.

It is not a de Polignac number, because 78424389 - 2⁷ = 78424261 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78424889) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 34902 + ... + 37080.

It is an arithmetic number, because the mean of its divisors is an integer number (3836800).

Almost surely, 2^78424389 is an apocalyptic number.

It is an amenable number.

78424389 is a deficient number, since it is larger than the sum of its proper divisors (44353211).

78424389 is a wasteful number, since it uses less digits than its factorization.

78424389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2262 (or 2256 counting only the distinct ones).

The product of its digits is 387072, while the sum is 45.

The square root of 78424389 is about 8855.7545697699. The cubic root of 78424389 is about 428.0393684490.

The spelling of 78424389 in words is "seventy-eight million, four hundred twenty-four thousand, three hundred eighty-nine".