28421945 has 4 divisors (see below), whose sum is σ = 34106340. Its totient is φ = 22737552.

The previous prime is 28421927. The next prime is 28421959. The reversal of 28421945 is 54912482.

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 8743849 + 19678096 = 2957^2 + 4436^2 .

It is a cyclic number.

It is not a de Polignac number, because 28421945 - 2⁶ = 28421881 is a prime.

It is a plaindrome in base 14.

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, 2842190 + ... + 2842199.

It is an arithmetic number, because the mean of its divisors is an integer number (8526585).

Almost surely, 2^28421945 is an apocalyptic number.

It is an amenable number.

28421945 is a deficient number, since it is larger than the sum of its proper divisors (5684395).

28421945 is an equidigital number, since it uses as much as digits as its factorization.

28421945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5684394.

The product of its digits is 23040, while the sum is 35.

The square root of 28421945 is about 5331.2235931351. The cubic root of 28421945 is about 305.1766243841.

The spelling of 28421945 in words is "twenty-eight million, four hundred twenty-one thousand, nine hundred forty-five".