28788139 has 2 divisors, whose sum is σ = 28788140. Its totient is φ = 28788138.

The previous prime is 28788103. The next prime is 28788143. The reversal of 28788139 is 93188782.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28788139 - 2²³ = 20399531 is a prime.

It is not a weakly prime, because it can be changed into another prime (28788239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14394069 + 14394070.

It is an arithmetic number, because the mean of its divisors is an integer number (14394070).

Almost surely, 2^28788139 is an apocalyptic number.

28788139 is a deficient number, since it is larger than the sum of its proper divisors (1).

28788139 is an equidigital number, since it uses as much as digits as its factorization.

28788139 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 193536, while the sum is 46.

The square root of 28788139 is about 5365.4579487682. The cubic root of 28788139 is about 306.4816875675.

The spelling of 28788139 in words is "twenty-eight million, seven hundred eighty-eight thousand, one hundred thirty-nine".