28205879 has 4 divisors (see below), whose sum is σ = 30375576. Its totient is φ = 26036184.

The previous prime is 28205857. The next prime is 28205897. The reversal of 28205879 is 97850282.

It is a happy number.

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 28205879 - 2²⁰ = 27157303 is a prime.

It is a super-2 number, since 2×28205879² = 1591143220325282, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28205809) 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, 1084829 + ... + 1084854.

It is an arithmetic number, because the mean of its divisors is an integer number (7593894).

Almost surely, 2^28205879 is an apocalyptic number.

28205879 is a deficient number, since it is larger than the sum of its proper divisors (2169697).

28205879 is a wasteful number, since it uses less digits than its factorization.

28205879 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2169696.

The product of its (nonzero) digits is 80640, while the sum is 41.

The square root of 28205879 is about 5310.9207299676. The cubic root of 28205879 is about 304.4013303725.

The spelling of 28205879 in words is "twenty-eight million, two hundred five thousand, eight hundred seventy-nine".