78805840 has 40 divisors (see below), whose sum is σ = 187130880. Its totient is φ = 30850176.

The previous prime is 78805823. The next prime is 78805873. The reversal of 78805840 is 4850887.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 78805793 and 78805802.

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 in 7 ways as a sum of consecutive naturals, for example, 6720 + ... + 14239.

It is an arithmetic number, because the mean of its divisors is an integer number (4678272).

Almost surely, 2^78805840 is an apocalyptic number.

It is an amenable number.

78805840 is an abundant number, since it is smaller than the sum of its proper divisors (108325040).

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

78805840 is a wasteful number, since it uses less digits than its factorization.

78805840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21019 (or 21013 counting only the distinct ones).

The product of its (nonzero) digits is 71680, while the sum is 40.

The square root of 78805840 is about 8877.2653446881. The cubic root of 78805840 is about 428.7322312985.

The spelling of 78805840 in words is "seventy-eight million, eight hundred five thousand, eight hundred forty".