28071978 has 16 divisors (see below), whose sum is σ = 61248096. Its totient is φ = 8506640.

The previous prime is 28071977. The next prime is 28071997. The reversal of 28071978 is 87917082.

It is not an unprimeable number, because it can be changed into a prime (28071973) 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 7 ways as a sum of consecutive naturals, for example, 212601 + ... + 212732.

It is an arithmetic number, because the mean of its divisors is an integer number (3828006).

Almost surely, 2^28071978 is an apocalyptic number.

28071978 is an abundant number, since it is smaller than the sum of its proper divisors (33176118).

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

28071978 is a wasteful number, since it uses less digits than its factorization.

28071978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 425349.

The product of its (nonzero) digits is 56448, while the sum is 42.

The square root of 28071978 is about 5298.2995385312. The cubic root of 28071978 is about 303.9188740704.

The spelling of 28071978 in words is "twenty-eight million, seventy-one thousand, nine hundred seventy-eight".