28108405 has 8 divisors (see below), whose sum is σ = 36324792. Its totient is φ = 20756928.

The previous prime is 28108393. The next prime is 28108417. The reversal of 28108405 is 50480182.

It is an interprime number because it is at equal distance from previous prime (28108393) and next prime (28108417).

It can be written as a sum of positive squares in 4 ways, for example, as 3437316 + 24671089 = 1854^2 + 4967^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28108405 - 2¹¹ = 28106357 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 7 ways as a sum of consecutive naturals, for example, 216154 + ... + 216283.

It is an arithmetic number, because the mean of its divisors is an integer number (4540599).

Almost surely, 2^28108405 is an apocalyptic number.

It is an amenable number.

28108405 is a deficient number, since it is larger than the sum of its proper divisors (8216387).

28108405 is a wasteful number, since it uses less digits than its factorization.

28108405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 432455.

The product of its (nonzero) digits is 2560, while the sum is 28.

The square root of 28108405 is about 5301.7360364318. The cubic root of 28108405 is about 304.0502751858.

Adding to 28108405 its reverse (50480182), we get a palindrome (78588587).

The spelling of 28108405 in words is "twenty-eight million, one hundred eight thousand, four hundred five".