28002509 has 2 divisors, whose sum is σ = 28002510. Its totient is φ = 28002508.

The previous prime is 28002479. The next prime is 28002511. The reversal of 28002509 is 90520082.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 24780484 + 3222025 = 4978^2 + 1795^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28002509 is a prime.

Together with 28002511, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28002529) by changing a digit.

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 as a sum of consecutive naturals, namely, 14001254 + 14001255.

It is an arithmetic number, because the mean of its divisors is an integer number (14001255).

Almost surely, 2^28002509 is an apocalyptic number.

It is an amenable number.

28002509 is a deficient number, since it is larger than the sum of its proper divisors (1).

28002509 is an equidigital number, since it uses as much as digits as its factorization.

28002509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 28002509 is about 5291.7396950341. The cubic root of 28002509 is about 303.6679669187.

The spelling of 28002509 in words is "twenty-eight million, two thousand, five hundred nine".