28638235 has 4 divisors (see below), whose sum is σ = 34365888. Its totient is φ = 22910584.

The previous prime is 28638209. The next prime is 28638277. The reversal of 28638235 is 53283682.

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 28638235 - 2⁷ = 28638107 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28638194 and 28638203.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2863819 + ... + 2863828.

It is an arithmetic number, because the mean of its divisors is an integer number (8591472).

Almost surely, 2^28638235 is an apocalyptic number.

28638235 is a deficient number, since it is larger than the sum of its proper divisors (5727653).

28638235 is an equidigital number, since it uses as much as digits as its factorization.

28638235 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5727652.

The product of its digits is 69120, while the sum is 37.

The square root of 28638235 is about 5351.4703586958. The cubic root of 28638235 is about 305.9487967354.

The spelling of 28638235 in words is "twenty-eight million, six hundred thirty-eight thousand, two hundred thirty-five".