78047920 has 20 divisors (see below), whose sum is σ = 181461600. Its totient is φ = 31219136.

The previous prime is 78047909. The next prime is 78047923. The reversal of 78047920 is 2974087.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (20).

It is a self number, because there is not a number n which added to its sum of digits gives 78047920.

It is not an unprimeable number, because it can be changed into a prime (78047923) 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, 487720 + ... + 487879.

It is an arithmetic number, because the mean of its divisors is an integer number (9073080).

Almost surely, 2^78047920 is an apocalyptic number.

It is an amenable number.

78047920 is an abundant number, since it is smaller than the sum of its proper divisors (103413680).

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

78047920 is a wasteful number, since it uses less digits than its factorization.

78047920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 975612 (or 975606 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 37.

The square root of 78047920 is about 8834.4733855505. The cubic root of 78047920 is about 427.3533484643.

The spelling of 78047920 in words is "seventy-eight million, forty-seven thousand, nine hundred twenty".