28461209 has 12 divisors (see below), whose sum is σ = 34251300. Its totient is φ = 23552928.

The previous prime is 28461163. The next prime is 28461229. The reversal of 28461209 is 90216482.

It can be written as a sum of positive squares in 2 ways, for example, as 11055625 + 17405584 = 3325^2 + 4172^2 .

It is not a de Polignac number, because 28461209 - 2¹² = 28457113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28461229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8594 + ... + 11435.

It is an arithmetic number, because the mean of its divisors is an integer number (2854275).

Almost surely, 2^28461209 is an apocalyptic number.

28461209 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

28461209 is a deficient number, since it is larger than the sum of its proper divisors (5790091).

28461209 is a wasteful number, since it uses less digits than its factorization.

28461209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20072 (or 20065 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 28461209 is about 5334.9047789066. The cubic root of 28461209 is about 305.3170902743.

The spelling of 28461209 in words is "twenty-eight million, four hundred sixty-one thousand, two hundred nine".