28278739 has 2 divisors, whose sum is σ = 28278740. Its totient is φ = 28278738.

The previous prime is 28278713. The next prime is 28278743. The reversal of 28278739 is 93787282.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28278739 - 2⁹ = 28278227 is a prime.

It is not a weakly prime, because it can be changed into another prime (28278779) 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, 14139369 + 14139370.

It is an arithmetic number, because the mean of its divisors is an integer number (14139370).

Almost surely, 2^28278739 is an apocalyptic number.

28278739 is a deficient number, since it is larger than the sum of its proper divisors (1).

28278739 is an equidigital number, since it uses as much as digits as its factorization.

28278739 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 338688, while the sum is 46.

The square root of 28278739 is about 5317.7757568367. The cubic root of 28278739 is about 304.6632097173.

The spelling of 28278739 in words is "twenty-eight million, two hundred seventy-eight thousand, seven hundred thirty-nine".