28139011 has 4 divisors (see below), whose sum is σ = 28165192. Its totient is φ = 28112832.

The previous prime is 28139003. The next prime is 28139017. The reversal of 28139011 is 11093182.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28139011 - 2³ = 28139003 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28139017) 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, 11406 + ... + 13651.

It is an arithmetic number, because the mean of its divisors is an integer number (7041298).

Almost surely, 2^28139011 is an apocalyptic number.

28139011 is a deficient number, since it is larger than the sum of its proper divisors (26181).

28139011 is a wasteful number, since it uses less digits than its factorization.

28139011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26180.

The product of its (nonzero) digits is 432, while the sum is 25.

The square root of 28139011 is about 5304.6216641717. The cubic root of 28139011 is about 304.1605907921.

The spelling of 28139011 in words is "twenty-eight million, one hundred thirty-nine thousand, eleven".