28139819 has 2 divisors, whose sum is σ = 28139820. Its totient is φ = 28139818.

The previous prime is 28139807. The next prime is 28139843. The reversal of 28139819 is 91893182.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28139819 is a prime.

It is a super-2 number, since 2×28139819² = 1583698826705522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (28139719) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14069909 + 14069910.

It is an arithmetic number, because the mean of its divisors is an integer number (14069910).

Almost surely, 2^28139819 is an apocalyptic number.

28139819 is a deficient number, since it is larger than the sum of its proper divisors (1).

28139819 is an equidigital number, since it uses as much as digits as its factorization.

28139819 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 31104, while the sum is 41.

The square root of 28139819 is about 5304.6978236277. The cubic root of 28139819 is about 304.1635020458.

The spelling of 28139819 in words is "twenty-eight million, one hundred thirty-nine thousand, eight hundred nineteen".