78839904 has 96 divisors (see below), whose sum is σ = 243177984. Its totient is φ = 22049280.

The previous prime is 78839899. The next prime is 78839947. The reversal of 78839904 is 40993887.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10857 + ... + 16599.

It is an arithmetic number, because the mean of its divisors is an integer number (2533104).

Almost surely, 2^78839904 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78839904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (121588992).

78839904 is an abundant number, since it is smaller than the sum of its proper divisors (164338080).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78839904 is a wasteful number, since it uses less digits than its factorization.

78839904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5780 (or 5772 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 48.

The square root of 78839904 is about 8879.1837462686. The cubic root of 78839904 is about 428.7939958876.

The spelling of 78839904 in words is "seventy-eight million, eight hundred thirty-nine thousand, nine hundred four".