28201009 has 2 divisors, whose sum is σ = 28201010. Its totient is φ = 28201008.

The previous prime is 28201007. The next prime is 28201031. The reversal of 28201009 is 90010282.

It is an a-pointer prime, because the next prime (28201031) can be obtained adding 28201009 to its sum of digits (22).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 24039409 + 4161600 = 4903^2 + 2040^2 .

It is a cyclic number.

It is not a de Polignac number, because 28201009 - 2¹ = 28201007 is a prime.

Together with 28201007, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (28201001) 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 as a sum of consecutive naturals, namely, 14100504 + 14100505.

It is an arithmetic number, because the mean of its divisors is an integer number (14100505).

Almost surely, 2^28201009 is an apocalyptic number.

It is an amenable number.

28201009 is a deficient number, since it is larger than the sum of its proper divisors (1).

28201009 is an equidigital number, since it uses as much as digits as its factorization.

28201009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 28201009 is about 5310.4622209371. The cubic root of 28201009 is about 304.3838101502.

The spelling of 28201009 in words is "twenty-eight million, two hundred one thousand, nine".