28139443 has 2 divisors, whose sum is σ = 28139444. Its totient is φ = 28139442.

The previous prime is 28139411. The next prime is 28139453. The reversal of 28139443 is 34493182.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28139443 - 2⁵ = 28139411 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 28139399 and 28139408.

It is not a weakly prime, because it can be changed into another prime (28139453) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14069721 + 14069722.

It is an arithmetic number, because the mean of its divisors is an integer number (14069722).

Almost surely, 2^28139443 is an apocalyptic number.

28139443 is a deficient number, since it is larger than the sum of its proper divisors (1).

28139443 is an equidigital number, since it uses as much as digits as its factorization.

28139443 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20736, while the sum is 34.

The square root of 28139443 is about 5304.6623832248. The cubic root of 28139443 is about 304.1621473109.

It can be divided in two parts, 28139 and 443, that added together give a palindrome (28582).

The spelling of 28139443 in words is "twenty-eight million, one hundred thirty-nine thousand, four hundred forty-three".