28661855 has 4 divisors (see below), whose sum is σ = 34394232. Its totient is φ = 22929480.

The previous prime is 28661839. The next prime is 28661879. The reversal of 28661855 is 55816682.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 55816682 = 2 ⋅27908341.

It is not a de Polignac number, because 28661855 - 2⁴ = 28661839 is a prime.

It is a Duffinian number.

It is a congruent number.

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, 2866181 + ... + 2866190.

It is an arithmetic number, because the mean of its divisors is an integer number (8598558).

Almost surely, 2^28661855 is an apocalyptic number.

28661855 is a deficient number, since it is larger than the sum of its proper divisors (5732377).

28661855 is an equidigital number, since it uses as much as digits as its factorization.

28661855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5732376.

The product of its digits is 115200, while the sum is 41.

The square root of 28661855 is about 5353.6767739564. The cubic root of 28661855 is about 306.0328862373.

The spelling of 28661855 in words is "twenty-eight million, six hundred sixty-one thousand, eight hundred fifty-five".