28209812 has 12 divisors (see below), whose sum is σ = 49484736. Its totient is φ = 14071320.

The previous prime is 28209803. The next prime is 28209821. The reversal of 28209812 is 21890282.

It is an interprime number because it is at equal distance from previous prime (28209803) and next prime (28209821).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6458 + ... + 9905.

It is an arithmetic number, because the mean of its divisors is an integer number (4123728).

Almost surely, 2^28209812 is an apocalyptic number.

It is an amenable number.

28209812 is a deficient number, since it is larger than the sum of its proper divisors (21274924).

28209812 is a wasteful number, since it uses less digits than its factorization.

28209812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16798 (or 16796 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 28209812 is about 5311.2909918399. The cubic root of 28209812 is about 304.4154781888.

The spelling of 28209812 in words is "twenty-eight million, two hundred nine thousand, eight hundred twelve".