28293905 has 4 divisors (see below), whose sum is σ = 33952692. Its totient is φ = 22635120.

The previous prime is 28293827. The next prime is 28293911. The reversal of 28293905 is 50939282.

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 4635409 + 23658496 = 2153^2 + 4864^2 .

It is not a de Polignac number, because 28293905 - 2¹⁴ = 28277521 is a prime.

It is a Duffinian 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, 2829386 + ... + 2829395.

It is an arithmetic number, because the mean of its divisors is an integer number (8488173).

Almost surely, 2^28293905 is an apocalyptic number.

It is an amenable number.

28293905 is a deficient number, since it is larger than the sum of its proper divisors (5658787).

28293905 is an equidigital number, since it uses as much as digits as its factorization.

28293905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5658786.

The product of its (nonzero) digits is 38880, while the sum is 38.

The square root of 28293905 is about 5319.2015378250. The cubic root of 28293905 is about 304.7176640134.

The spelling of 28293905 in words is "twenty-eight million, two hundred ninety-three thousand, nine hundred five".