28161449 has 4 divisors (see below), whose sum is σ = 28174164. Its totient is φ = 28148736.

The previous prime is 28161421. The next prime is 28161473. The reversal of 28161449 is 94416182.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 14707225 + 13454224 = 3835^2 + 3668^2 .

It is a cyclic number.

It is not a de Polignac number, because 28161449 - 2⁸ = 28161193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28161649) 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, 2072 + ... + 7785.

It is an arithmetic number, because the mean of its divisors is an integer number (7043541).

Almost surely, 2^28161449 is an apocalyptic number.

It is an amenable number.

28161449 is a deficient number, since it is larger than the sum of its proper divisors (12715).

28161449 is an equidigital number, since it uses as much as digits as its factorization.

28161449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12714.

The product of its digits is 13824, while the sum is 35.

The square root of 28161449 is about 5306.7361909181. The cubic root of 28161449 is about 304.2414150272.

The spelling of 28161449 in words is "twenty-eight million, one hundred sixty-one thousand, four hundred forty-nine".