28128105 has 24 divisors (see below), whose sum is σ = 48991488. Its totient is φ = 14929056.

The previous prime is 28128101. The next prime is 28128109. The reversal of 28128105 is 50182182.

It is an interprime number because it is at equal distance from previous prime (28128101) and next prime (28128109).

It is not a de Polignac number, because 28128105 - 2² = 28128101 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28128101) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8634 + ... + 11436.

It is an arithmetic number, because the mean of its divisors is an integer number (2041312).

Almost surely, 2^28128105 is an apocalyptic number.

It is an amenable number.

28128105 is a deficient number, since it is larger than the sum of its proper divisors (20863383).

28128105 is a wasteful number, since it uses less digits than its factorization.

28128105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3037 (or 3034 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 27.

The square root of 28128105 is about 5303.5935930273. The cubic root of 28128105 is about 304.1212906185.

The spelling of 28128105 in words is "twenty-eight million, one hundred twenty-eight thousand, one hundred five".