28656623 has 4 divisors (see below), whose sum is σ = 29197368. Its totient is φ = 28115880.

The previous prime is 28656601. The next prime is 28656671. The reversal of 28656623 is 32665682.

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 28656623 - 2¹² = 28652527 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28652623) 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, 270293 + ... + 270398.

It is an arithmetic number, because the mean of its divisors is an integer number (7299342).

Almost surely, 2^28656623 is an apocalyptic number.

28656623 is a deficient number, since it is larger than the sum of its proper divisors (540745).

28656623 is an equidigital number, since it uses as much as digits as its factorization.

28656623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 540744.

The product of its digits is 103680, while the sum is 38.

The square root of 28656623 is about 5353.1881155065. The cubic root of 28656623 is about 306.0142637918.

The spelling of 28656623 in words is "twenty-eight million, six hundred fifty-six thousand, six hundred twenty-three".