28072817 has 2 divisors, whose sum is σ = 28072818. Its totient is φ = 28072816.

The previous prime is 28072813. The next prime is 28072819. The reversal of 28072817 is 71827082.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15335056 + 12737761 = 3916^2 + 3569^2 .

It is a cyclic number.

It is not a de Polignac number, because 28072817 - 2² = 28072813 is a prime.

Together with 28072819, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p_1745684 and since 28072817 and 1745684 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (28072813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14036408 + 14036409.

It is an arithmetic number, because the mean of its divisors is an integer number (14036409).

Almost surely, 2^28072817 is an apocalyptic number.

It is an amenable number.

28072817 is a deficient number, since it is larger than the sum of its proper divisors (1).

28072817 is an equidigital number, since it uses as much as digits as its factorization.

28072817 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12544, while the sum is 35.

The square root of 28072817 is about 5298.3787142861. The cubic root of 28072817 is about 303.9219018276.

Adding to 28072817 its reverse (71827082), we get a palindrome (99899899).

The spelling of 28072817 in words is "twenty-eight million, seventy-two thousand, eight hundred seventeen".