28155851 has 4 divisors (see below), whose sum is σ = 28201104. Its totient is φ = 28110600.

The previous prime is 28155847. The next prime is 28155857. The reversal of 28155851 is 15855182.

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 28155851 - 2² = 28155847 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28155857) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21680 + ... + 22941.

It is an arithmetic number, because the mean of its divisors is an integer number (7050276).

Almost surely, 2^28155851 is an apocalyptic number.

28155851 is a deficient number, since it is larger than the sum of its proper divisors (45253).

28155851 is an equidigital number, since it uses as much as digits as its factorization.

28155851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45252.

The product of its digits is 16000, while the sum is 35.

The square root of 28155851 is about 5306.2087218654. The cubic root of 28155851 is about 304.2212544132.

The spelling of 28155851 in words is "twenty-eight million, one hundred fifty-five thousand, eight hundred fifty-one".