78928420 has 12 divisors (see below), whose sum is σ = 165749724. Its totient is φ = 31571360.

The previous prime is 78928393. The next prime is 78928427. The reversal of 78928420 is 2482987.

It can be written as a sum of positive squares in 2 ways, for example, as 55830784 + 23097636 = 7472^2 + 4806^2 .

It is not an unprimeable number, because it can be changed into a prime (78928427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1973191 + ... + 1973230.

It is an arithmetic number, because the mean of its divisors is an integer number (13812477).

Almost surely, 2^78928420 is an apocalyptic number.

It is an amenable number.

78928420 is an abundant number, since it is smaller than the sum of its proper divisors (86821304).

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

78928420 is a wasteful number, since it uses less digits than its factorization.

78928420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3946430 (or 3946428 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 40.

The square root of 78928420 is about 8884.1668151831. The cubic root of 78928420 is about 428.9544092984.

The spelling of 78928420 in words is "seventy-eight million, nine hundred twenty-eight thousand, four hundred twenty".