28875139 has 4 divisors (see below), whose sum is σ = 29012200. Its totient is φ = 28738080.

The previous prime is 28875113. The next prime is 28875169. The reversal of 28875139 is 93157882.

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 28875139 - 2⁵ = 28875107 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28875095 and 28875104.

It is not an unprimeable number, because it can be changed into a prime (28875169) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68214 + ... + 68635.

It is an arithmetic number, because the mean of its divisors is an integer number (7253050).

Almost surely, 2^28875139 is an apocalyptic number.

28875139 is a deficient number, since it is larger than the sum of its proper divisors (137061).

28875139 is a wasteful number, since it uses less digits than its factorization.

28875139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137060.

The product of its digits is 120960, while the sum is 43.

The square root of 28875139 is about 5373.5592487661. The cubic root of 28875139 is about 306.7901142623.

The spelling of 28875139 in words is "twenty-eight million, eight hundred seventy-five thousand, one hundred thirty-nine".