28639207 has 2 divisors, whose sum is σ = 28639208. Its totient is φ = 28639206.

The previous prime is 28639157. The next prime is 28639223. The reversal of 28639207 is 70293682.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28639207 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28639267) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14319603 + 14319604.

It is an arithmetic number, because the mean of its divisors is an integer number (14319604).

Almost surely, 2^28639207 is an apocalyptic number.

28639207 is a deficient number, since it is larger than the sum of its proper divisors (1).

28639207 is an equidigital number, since it uses as much as digits as its factorization.

28639207 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36288, while the sum is 37.

The square root of 28639207 is about 5351.5611740874. The cubic root of 28639207 is about 305.9522580621.

It can be divided in two parts, 286 and 39207, that added together give a palindrome (39493).

The spelling of 28639207 in words is "twenty-eight million, six hundred thirty-nine thousand, two hundred seven".