28121678 has 16 divisors (see below), whose sum is σ = 45872736. Its totient is φ = 12852000.

The previous prime is 28121657. The next prime is 28121707. The reversal of 28121678 is 87612182.

It is a Curzon number.

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, 2573 + ... + 7928.

It is an arithmetic number, because the mean of its divisors is an integer number (2867046).

Almost surely, 2^28121678 is an apocalyptic number.

28121678 is a deficient number, since it is larger than the sum of its proper divisors (17751058).

28121678 is a wasteful number, since it uses less digits than its factorization.

28121678 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10619.

The product of its digits is 10752, while the sum is 35.

The square root of 28121678 is about 5302.9876484865. The cubic root of 28121678 is about 304.0981259294.

The spelling of 28121678 in words is "twenty-eight million, one hundred twenty-one thousand, six hundred seventy-eight".