28021207 has 2 divisors, whose sum is σ = 28021208. Its totient is φ = 28021206.

The previous prime is 28021193. The next prime is 28021237. The reversal of 28021207 is 70212082.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28021207 - 2¹⁵ = 27988439 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28021237) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14010603 + 14010604.

It is an arithmetic number, because the mean of its divisors is an integer number (14010604).

Almost surely, 2^28021207 is an apocalyptic number.

28021207 is a deficient number, since it is larger than the sum of its proper divisors (1).

28021207 is an equidigital number, since it uses as much as digits as its factorization.

28021207 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 448, while the sum is 22.

The square root of 28021207 is about 5293.5061159878. The cubic root of 28021207 is about 303.7355408676.

Adding to 28021207 its reverse (70212082), we get a palindrome (98233289).

The spelling of 28021207 in words is "twenty-eight million, twenty-one thousand, two hundred seven".