28406905 has 4 divisors (see below), whose sum is σ = 34088292. Its totient is φ = 22725520.

The previous prime is 28406879. The next prime is 28406923. The reversal of 28406905 is 50960482.

It is a happy number.

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 10942864 + 17464041 = 3308^2 + 4179^2 .

It is not a de Polignac number, because 28406905 - 2⁹ = 28406393 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, 2840686 + ... + 2840695.

It is an arithmetic number, because the mean of its divisors is an integer number (8522073).

Almost surely, 2^28406905 is an apocalyptic number.

It is an amenable number.

28406905 is a deficient number, since it is larger than the sum of its proper divisors (5681387).

28406905 is an equidigital number, since it uses as much as digits as its factorization.

28406905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5681386.

The product of its (nonzero) digits is 17280, while the sum is 34.

The square root of 28406905 is about 5329.8128484967. The cubic root of 28406905 is about 305.1227849269.

The spelling of 28406905 in words is "twenty-eight million, four hundred six thousand, nine hundred five".