28281101 has 6 divisors (see below), whose sum is σ = 29848302. Its totient is φ = 26792280.

The previous prime is 28281091. The next prime is 28281151. The reversal of 28281101 is 10118282.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 26512201 + 1768900 = 5149^2 + 1330^2 .

It is not a de Polignac number, because 28281101 - 2⁶ = 28281037 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 (28281151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 38810 + ... + 39531.

It is an arithmetic number, because the mean of its divisors is an integer number (4974717).

Almost surely, 2^28281101 is an apocalyptic number.

It is an amenable number.

28281101 is a deficient number, since it is larger than the sum of its proper divisors (1567201).

28281101 is an equidigital number, since it uses as much as digits as its factorization.

28281101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78379 (or 78360 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 23.

The square root of 28281101 is about 5317.9978375325. The cubic root of 28281101 is about 304.6716918785.

Adding to 28281101 its sum of digits (23), we get a square (28281124 = 5318²).

Adding to 28281101 its reverse (10118282), we get a palindrome (38399383).

It can be divided in two parts, 28281 and 101, that added together give a palindrome (28382).

The spelling of 28281101 in words is "twenty-eight million, two hundred eighty-one thousand, one hundred one".