28488109 has 4 divisors (see below), whose sum is σ = 30679516. Its totient is φ = 26296704.

The previous prime is 28488067. The next prime is 28488127. The reversal of 28488109 is 90188482.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11923209 + 16564900 = 3453^2 + 4070^2 .

It is a cyclic number.

It is not a de Polignac number, because 28488109 - 2⁷ = 28487981 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 (28488139) 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, 1095684 + ... + 1095709.

It is an arithmetic number, because the mean of its divisors is an integer number (7669879).

Almost surely, 2^28488109 is an apocalyptic number.

It is an amenable number.

28488109 is a deficient number, since it is larger than the sum of its proper divisors (2191407).

28488109 is a wasteful number, since it uses less digits than its factorization.

28488109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2191406.

The product of its (nonzero) digits is 36864, while the sum is 40.

The square root of 28488109 is about 5337.4253156367. The cubic root of 28488109 is about 305.4132497357.

The spelling of 28488109 in words is "twenty-eight million, four hundred eighty-eight thousand, one hundred nine".