28809978 has 16 divisors (see below), whose sum is σ = 57736416. Its totient is φ = 9583920.

The previous prime is 28809967. The next prime is 28809983. The reversal of 28809978 is 87990882.

It is a self number, because there is not a number n which added to its sum of digits gives 28809978.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1453 + ... + 7728.

It is an arithmetic number, because the mean of its divisors is an integer number (3608526).

Almost surely, 2^28809978 is an apocalyptic number.

28809978 is an abundant number, since it is smaller than the sum of its proper divisors (28926438).

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

28809978 is a wasteful number, since it uses less digits than its factorization.

28809978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9709.

The product of its (nonzero) digits is 580608, while the sum is 51.

The square root of 28809978 is about 5367.4927107542. The cubic root of 28809978 is about 306.5591681086.

The spelling of 28809978 in words is "twenty-eight million, eight hundred nine thousand, nine hundred seventy-eight".